sentinel
gb/sˈɛntənəl/ us/sˈɛntənəl/
C1
อังกฤษ
~ 9000
ความหมาย
0 ความหมาย
คำนาม
C1
entity
1
person or thing that guards
A person, animal, or device that stays in one place to watch and protect something or someone.
รูปแบบการใช้:
[someone/something] is a sentinel for [a place/person]
ข้อผิดพลาดที่พบบ่อย:
Learners sometimes think "sentinel" can mean any security device or system (like a password or alarm). It specifically refers to a watcher or guard (person, animal, or guarding object like a tower or device), not just any safety measure.
คำพ้องความหมาย
guard (General word for someone who protects people or property; more common and less formal than "sentinel".)
|
lookout (Focuses on the act of watching for danger, not on formally guarding a place like a sentinel often does.)
คำตรงข้าม
intruder (Opposite role: someone who enters a place without permission instead of protecting it.)
คำที่ใช้ร่วมกัน
lone sentinel
|stand sentinel
|silent sentinel
|post a sentinel
|act as a sentinel
หัวข้อ
security
|military
|nature
|core_vocabulary
|daily_life
ตัวอย่าง
- A lone sentinel stood at the gate throughout the night.
- Two soldiers were posted as sentinels along the perimeter fence.
- From the hill, a stone tower acts as a sentinel over the harbor below.
- The old lighthouse, now automated, still serves as a silent sentinel for passing ships.
- His dog was a constant sentinel at the front door, barking at any unexpected visitor.
ตัวอย่างสำหรับผู้เรียน
- A soldier stood as a sentinel at the door.
- The big tree was like a sentinel at the edge of the field.
- A dog can be a good sentinel for a house.
- The statue is a stone sentinel in front of the museum.
คำนาม
technical
C2
entity
2
marker value in programming
In computer programs, a special number or value used to show the end of a list or to show that something special has happened.
รูปแบบการใช้:
[someone] uses a sentinel to mark [an end/boundary]
ข้อผิดพลาดที่พบบ่อย:
Learners may confuse a "sentinel" with any error code. A sentinel can mark many special conditions, including normal ends of data, and is not only for errors.
คำพ้องความหมาย
marker (Broad technical term for something that shows a position or condition; not specific to data values like "sentinel" often is.)
|
flag (Common programming term for a variable that signals a condition; overlaps with sentinel but not always used to mark ends of structures.)
คำตรงข้าม
ordinary value (A regular data value that carries normal content, not used specially to mark structure or conditions like a sentinel does.)
คำที่ใช้ร่วมกัน
sentinel value
|sentinel node
|sentinel character
|use a sentinel
|special sentinel
หัวข้อ
technology
|computer_science
|science
|education
ตัวอย่าง
- The loop reads input until it encounters the sentinel value of -1.
- We added a null byte as a sentinel character to mark the end of the string.
- Using a sentinel in the array helps simplify the search algorithm.
- The linked list uses a sentinel node at the head to avoid special-case code.
- A unique sentinel object is often used to distinguish "no value" from "None" in Python functions.
ตัวอย่างสำหรับผู้เรียน
- The program stops when it sees the sentinel value.
- We use -1 as a sentinel to show the end of the list.
- A sentinel value makes the code easier to read.
- The array has a sentinel at the end so the loop knows when to stop.
คำนาม
technical
C2
event
3
early warning safety event
A very serious or first case of a problem that warns people there may be a bigger safety or health problem.
รูปแบบการใช้:
[something] is a sentinel event for [a larger problem]
ข้อผิดพลาดที่พบบ่อย:
Learners may think "sentinel event" simply means any important event. In professional healthcare and safety contexts, it is a specific kind of serious incident that must be analyzed and often reported.
คำพ้องความหมาย
warning sign (General and informal; does not carry the technical, reportable meaning that "sentinel event" has in healthcare.)
|
red flag (Informal expression for a strong warning; lacks the formal, technical sense of an event that must be investigated.)
คำตรงข้าม
routine event (A normal, expected event that does not signal a hidden problem, unlike a sentinel event.)
คำที่ใช้ร่วมกัน
sentinel event
|sentinel case
|sentinel injury
|sentinel surveillance
หัวข้อ
healthcare
|safety
|health
|law
|work
ตัวอย่าง
- The unexpected patient death was classified as a sentinel event and triggered a full investigation.
- A single case of polio can be a sentinel event for broader community transmission.
- The hospital tracks every fall as a potential sentinel event indicating problems in patient safety.
- Public health officials treated the first local dengue case as a sentinel case for the region.
- The explosion was a sentinel event that revealed major failures in the plant’s safety systems.
ตัวอย่างสำหรับผู้เรียน
- The hospital called the accident a sentinel event.
- One serious mistake can be a sentinel event for a hospital.
- A sentinel event shows there may be a bigger safety problem.
- The first case of the disease was a sentinel case for the area.
คำนาม
technical
C2
entity
4
organism that signals risk
An animal or other living thing that shows early signs of damage when the environment is dangerous or polluted.
รูปแบบการใช้:
[something] is a sentinel species for [a condition/place]
ข้อผิดพลาดที่พบบ่อย:
Learners might confuse a "sentinel species" with a "keystone species". A keystone species strongly shapes an ecosystem; a sentinel species is mainly valued as an early warning sign.
คำพ้องความหมาย
indicator species (Broader ecological term; not all indicator species are specifically used as early warning sentinels for danger.)
คำตรงข้าม
non-indicator species (A species whose presence or health does not clearly show changes in environmental conditions, unlike a sentinel species.)
คำที่ใช้ร่วมกัน
sentinel species
|sentinel animal
|environmental sentinel
|avian sentinel
หัวข้อ
environment
|biology
|nature
|science
|health
ตัวอย่าง
- Frogs are often used as sentinel species because their skin is highly sensitive to pollutants.
- Marine biologists chose sea lions as sentinel animals to monitor ocean health.
- Bird die-offs can act as a sentinel for emerging infectious diseases like West Nile virus.
- Bees serve as environmental sentinels, reacting quickly to pesticide exposure.
- The decline of lichen on trees became a sentinel of worsening air quality in the region.
ตัวอย่างสำหรับผู้เรียน
- Scientists use some animals as sentinel species to watch for pollution.
- Dead birds can be a sentinel for a new disease in an area.
- Frogs are sentinels for water pollution because they are very sensitive.
- Bees can be sentinels of bad chemicals in the environment.
คำกริยา
literary
C2
action
5
stand guard over something
To stay in one place to watch and protect a place or person.
รูปแบบการใช้:
[someone/something] sentinels [a place/person]
ข้อผิดพลาดที่พบบ่อย:
Learners often do not recognize "sentinel" as a verb and may think usages like "trees sentinel the path" are errors. It is rare and mainly literary; in normal speech, "guard" or "stand guard over" is preferred.
คำพ้องความหมาย
guard (More common general verb; "sentinel" is rarer and more literary, suggesting a fixed, watchful presence.)
|
watch over (Softer and more emotional; "sentinel" sounds more formal and duty-focused.)
คำตรงข้าม
neglect (To fail to protect or watch something, the opposite of actively sentineling it.)
คำที่ใช้ร่วมกัน
sentinel the border
|sentinel the camp
|sentinel the gates
หัวข้อ
security
|literature
|core_vocabulary
|daily_life
ตัวอย่าง
- Armed troops sentinel the narrow pass leading into the valley.
- A line of ancient oaks sentinels the driveway to the old estate.
- Volunteers now sentinel the entrance to the camp through the night.
- High stone towers sentinel the harbor, their lights sweeping the dark water.
- Two police officers sentinel the door while the search is carried out inside.
ตัวอย่างสำหรับผู้เรียน
- Soldiers sentinel the gate all night.
- Tall trees sentinel the road to the house.
- Guards sentinel the door during the meeting.
- Police officers sentinel the front of the building.
ไวยากรณ์
วลีและสำนวน
act as a sentinel
1/ˈækt ˈæz ə sˈɛntənəl/
fixed phrase
serve in a guarding role
To have the job of watching and protecting something or someone.
ตัวอย่าง
- The security cameras act as sentinels for the parking lot.
- Her dog acts as a sentinel, barking at any strange sound outside the house.
sentinel event
1/sˈɛntənəl ɪvˈɛnt/
fixed phrase
technical
serious incident that signals danger
A very serious and unexpected mistake or problem in a hospital or other service that shows something is badly wrong and must be studied.
ตัวอย่าง
- The patient’s suicide was reported as a sentinel event under hospital policy.
- Any wrong-site surgery is automatically classified as a sentinel event.
sentinel node
1/sˈɛntənəl nˈoʊd/
fixed phrase
technical
first lymph node cancer reaches
The first lymph node where cancer cells are likely to go from the main tumor.
ตัวอย่าง
- The surgeon removed the sentinel node to check whether the cancer had spread.
- A biopsy of the sentinel node came back negative, which was good news for the patient.
sentinel species
1/sˈɛntənəl spˈiʃiz/
fixed phrase
technical
species that warns of danger
A kind of animal or other living thing that shows early signs when the environment becomes dangerous or polluted.
ตัวอย่าง
- Biologists chose frogs as a sentinel species for water quality in the wetlands.
- Changes in bee behavior can make them a useful sentinel species for pesticide exposure.
sentinel value
1/sˈɛntənəl vˈælju/
fixed phrase
technical
special marker value in code
A special number or value in a computer program that shows the end of data or a special state.
ตัวอย่าง
- We use -999 as a sentinel value to show missing test scores.
- The loop stops reading input when it finds the sentinel value.
stand sentinel
1/stˈænd sˈɛntənəl/
fixed phrase
literary
stand as a guard
To stand in one place to watch and protect a place or person.
ตัวอย่าง
- Two soldiers stood sentinel outside the president’s room.
- A lone pine tree stands sentinel at the edge of the cliff.