imaginary

/i'mædʤinəri/

Thân thiện

A child plays with an imaginary friend in the backyard.

Definition

1. Adjective:

   • Not based on fact; unreal: Existing only in the imagination or as a concept, not in physical reality.
   • Fanciful or invented: Created by or existing in the mind, often as a product of creativity or fantasy.

2. Noun:

   • (Mathematics): A number that can be expressed in the form a + bi, where a and b are real numbers, and i is the square root of -1.

Usage Examples

• Adjective:

  • The child had an imaginary friend named Leo. (The friend existed only in the child's mind.)
  • The story is set in an imaginary kingdom. (The kingdom is not a real place.)
  • Her fears were mostly imaginary. (The fears were not based on real threats.)

• Noun:

  • In this equation, you must account for the imaginary. (The mathematical component involving i must be considered.)

Advanced Usage

• "Purely imaginary" (Mathematics): A complex number where the real part () is zero (e.g., 5).
• "Imaginary axis": The vertical axis on the complex plane representing imaginary numbers.
• "Imaginary line": A conceptual line used for measurement or division, not physically drawn (e.g., the equator is real, but a line dividing a room is imaginary).

Variants and Related Words

• Imagine (verb): To form a mental image or concept of something.
• Imagination (noun): The faculty or action of forming new ideas, images, or concepts not present to the senses.
• Imaginative (adjective): Having or showing creativity or inventiveness.
• Imaginable (adjective): Able to be imagined or conceived.

Synonyms

• Fictional: Relating to or occurring in fiction; invented.
• Unreal: Not real or actual.
• Fanciful: Over-imaginative and unrealistic.
• Illusory: Based on illusion; not real.
• Mythical: Occurring in or characteristic of myths or folk tales.

Antonyms

• Real: Actually existing as a thing or occurring in fact.
• Actual: Existing in fact; real.
• Tangible: Perceptible by touch; clear and definite; real.
• Concrete: Existing in a material or physical form; real.

Related Phrases and Concepts

• Imaginary number: The core mathematical term, as defined in the noun sense.
• Imaginary unit (i): The square root of -1, the fundamental component of an imaginary number.
• Complex number: A number containing both a real part and an imaginary part (e.g., 3 + 2).

Học thuật

Adjective

1. not based on fact; unreal
   • the falsehood about some fanciful secret treaties- F.D.Roosevelt
   • a small child's imaginary friends
   • to create a notional world for oneself

Noun

1. (mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1

Từ đồng nghĩa

• fanciful
• notional
• complex number
• complex quantity
• imaginary number