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REFERENCE

prime

adj. · n. · v.
US //ˈpɹaɪm// UK //pɹˈaɪm// prime
  1. 1 best or most important (adj.)
    B2 Upper Intermediate

    of the best quality or the most important.

    first in importance, degree, or quality; often used to describe the most relevant or excellent example of something.

    Example

    The hotel is in a prime location right next to the city's main square.

    Example

    The property's prime location in the financial district ensures that its market value remains high despite economic fluctuations.
  2. 2 mathematics (adj.)
    B2 Upper Intermediate Technical Math

    describes a number that can only be divided by itself and the number one.

    relating to a positive integer greater than one that has no positive integer divisors other than one and itself.

    Example

    Seven is a prime number because you cannot divide it by two, three, or four.

    Example

    Encryption algorithms often rely on the mathematical difficulty of factoring the product of two large prime numbers.
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  1. 3 the best period of life (n.)
    B2 Upper Intermediate

    the time in your life when you are strongest, most successful, or most beautiful.

    the state or time of greatest vigour, strength, or success in a person's life or a thing's existence.

    Example

    The athlete was in his prime when he won the gold medal.

    Example

    Many critics argue that the painter reached her artistic prime during her years in Paris, before her style became more commercial.
  2. 4 to apply a base coat (v.)
    B2 Upper Intermediate Technical

    to put a first layer of special paint on a surface before the main paint.

    to apply a coat of primer to a surface to prepare it for a finished layer of paint or varnish.

    Example

    You need to prime the wooden door before you paint it blue.

    Example

    Failure to prime the metal surface correctly will result in the topcoat peeling off within a few months of exposure to the elements.
  3. 5 to make a pump or engine ready (v.)
    C1 Advanced Technical

    to put liquid into a pump or engine so that it can start working.

    to pour liquid into a pump or to supply fuel to an engine to prepare it for operation.

    Example

    He had to prime the old water pump before any water would come out.

    Example

    The mechanic explained that you must prime the fuel system manually if the vehicle has been sitting idle for several years.
Etymology 1

From Middle English prime, from Old French prime and its etymon, Latin prīmus (“first”), from earlier prīsmos < prīsemos < Proto-Italic priisemos, ultimately from Proto-Indo-European *per- (“beyond, before”). Doublet of primo and primus. The noun sense "apostrophe-like symbol" originates from the fact that the symbol ′ was originally a superscript Roman numeral one.

Etymology 2

Related to primage and Latin prīmus.

Etymology 3

From French prime (“reward, prize, bonus”).

Idioms2 entries

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