costly
gb/kˈɔstli/ us/kˈɔstli/
B1
Anglais
~ 10100
Sens
0 sens
adjective
B1
property
1
expensive; high in money cost
Needing a lot of money to buy, use, or keep; expensive.
Schéma d’usage :
[something] is costly
Erreur fréquente :
Learners sometimes use "costly" only for mistakes or losses and forget it also simply means "expensive" in money. Also, some learners try to use it as an adverb (e.g., *"He paid costly for it"*), but the correct forms are "dearly" or "at a high cost" ("He paid dearly for it").
Synonymes
expensive (The most common and neutral synonym; slightly more frequent than "costly" in everyday speech.)
|
pricey (Informal and slightly more casual; often used in spoken English.)
Antonymes
cheap (Suggests low cost and sometimes low quality; more informal than "inexpensive".)
|
inexpensive (Neutral word meaning not expensive; does not suggest low quality.)
Collocations
costly equipment
|costly repairs
|costly treatment
|costly project
|highly costly
|too costly
Thèmes
money
|business
|daily life
|finance
|core_vocabulary
Exemples
- Health insurance can be very costly in the United States.
- Replacing the broken engine was more costly than buying a new car.
- The company canceled the trip because it was too costly for their budget.
- Energy-efficient lights are costly at first but save money over time.
- Parking in the city center is often quite costly.
Exemples pédagogiques
- The new phone is too costly for me.
- Studying abroad can be very costly.
- This hotel is nice, but it is costly.
- Rent in this area is very costly.
- The repair was more costly than I expected.
adjective
B2
property
2
causing serious loss or damage
Causing big loss, harm, or problems, not only about money.
Schéma d’usage :
a costly [mistake/decision/error]
Erreur fréquente :
Learners often think "costly" only talks about money. In this sense, it is used for mistakes, errors, defeats, or decisions that cause serious loss (time, reputation, chances, lives), not just financial cost. Learners may also say *"very big mistake"* where "costly mistake" is more natural in English.
Synonymes
damaging (Emphasizes harm or injury caused, not just the size of the loss.)
|
disastrous (Stronger and more emotional; suggests extremely bad, possibly disastrous, results.)
Antonymes
harmless (Suggests that an action or mistake does not cause harm or serious negative results.)
|
beneficial (Focuses on producing good or helpful results, the opposite of causing loss.)
Collocations
costly mistake
|costly error
|costly decision
|costly defeat
|costly delay
|prove costly
Thèmes
consequences
|sports
|work
|core_vocabulary
Exemples
- His refusal to listen to advice turned out to be a costly mistake.
- The team’s costly errors in the final minutes lost them the game.
- Ignoring these safety rules can be extremely costly for the company.
- The delay in responding to the crisis proved costly to her reputation.
- That risky investment decision was costly for the entire organization.
Exemples pédagogiques
- It was a costly mistake, and they lost the contract.
- Her costly error changed the result of the game.
- Not saving your work on the computer can be costly.
- Their late response to the problem was very costly.
- His lie was costly, and he lost many friends.
Grammaire
Forme canonique
costly
API
GB/kˈɔstli/
US/kˈɔstli/
Syllabes et accentuation
costly (1 syllabe)
Stress on 1st syllable (costly)
Formes du mot
Adjective
- Base: costly
- Comparative: costlier
- Superlative: costliest
Famille de mots
Forms
costlier
adjective
costliest
adjective
Core family
cost
noun A2
Negative and opposite forms
cheap
adjective A1
inexpensive
adjective B1
Advanced or less common
costliness
noun
Expressions
costly mistake
1/kˈɔstli mɪstˈeɪk/
fixed phrase
a mistake with serious consequences
A mistake that causes serious loss, harm, or problems.
Exemples
- Forgetting to back up the data was a costly mistake for the company.
- His joke about the client turned into a costly mistake when she heard it.
- Leaving the star player on the bench proved to be a costly mistake.
costly victory
1/kˈɔstli vˈɪktɚi/
fixed phrase
a win with heavy losses
A win or success that comes with serious loss or harm, so it almost feels not worth it.
Exemples
- The army won a costly victory, losing many soldiers in the battle.
- It was a costly victory for the team, as their best player was badly injured.
- The company’s legal win was a costly victory that damaged its public image.
prove costly
1/pɹˈuv kˈɔstli/
fixed phrase
end up causing serious loss
To finally cause serious loss, harm, or problems, often after some time.
Exemples
- Ignoring these warnings could prove costly in the long run.
- The coach’s decision to change the lineup proved costly.
- Their choice to delay the product launch may prove costly for the brand.