imaginary
not real, only in the mind
Not real; only in your mind, not in the real world.
an imaginary [thing/person/place]
- As a child, she had an imaginary friend who went everywhere with her.
- The danger he described was mostly imaginary, not something we really needed to worry about.
- The story takes place in an imaginary city somewhere in the Pacific.
- He lives in an imaginary world where nothing ever goes wrong.
- Many children talk to an imaginary friend.
- The monster under the bed is imaginary.
- She wrote a story about an imaginary country.
- His fears about losing his job were mostly imaginary.
mathematical, involving √−1
In math, used about numbers that include the special value √−1, called i, and are not real numbers.
an imaginary [number/part/unit]
- In this equation, x is a real number and y is an imaginary number.
- Every complex number can be written as a real part plus an imaginary part.
- The imaginary unit, usually written as i, is defined as the square root of minus one.
- In algebra class we learned about imaginary numbers.
- A complex number has a real part and an imaginary part.
- The symbol i is used for the imaginary unit.
an imaginary number in math
In math, an "imaginary" is a number that is a real number times √−1.
an imaginary
- In this context, z is a pure imaginary, with no real part.
- The solution of the equation is not a real number but an imaginary.
- Engineers often work with imaginaries when analyzing alternating current circuits.
- The answer is not a real number; it is an imaginary.
- In higher math, students learn about reals and imaginaries.
- This equation has two solutions, both of them imaginaries.
- Base: imaginary
- Base: imaginary
- Plural: imaginaries
imaginary friend
1a made-up friend in the mind
A friend that someone, especially a child, makes up in their mind and talks or plays with as if the friend is real.
- Their daughter talks to her imaginary friend every night before bed.
- As a child, I had an imaginary friend who went on adventures with me.
imaginary line
1a non-physical dividing line
A line that people talk about for maps, borders, or explanations, but that you cannot see or touch in the real world.
- The equator is an imaginary line around the middle of the Earth.
- There is an imaginary line between work and home that he tries not to cross with his problems.
imaginary number
1number involving √−1 in math
In math, a number that is a real number times √−1, written with the symbol i.
- The equation x² + 1 = 0 has two imaginary numbers as solutions.
- Imaginary numbers are used together with real numbers to form complex numbers.
purely imaginary
1complex number with no real part
In math, used for a complex number that has no real part, only an imaginary part.
- If the real part is zero, the complex number is purely imaginary.
- The solutions to this equation are purely imaginary and lie on the vertical axis of the complex plane.