prime

Concise Oxford English Dictionary © 2008 Oxford University Press:
prime1

▶adjective

• 1 of first importance; main; primary.

• 2 of the best possible quality; excellent.

  ■ having all the expected characteristics.

  ■ most suitable or likely.

• 3 (of a number) divisible only by itself and one (e.g. 2, 3, 5, 7, 11).

▶noun

• 1 a state or time of greatest vigour or success in a person's life.

  ■ archaic the beginning or earliest period.

• 2 a prime number.

• 3 Printing a symbol (′) written as a distinguishing mark or to denote minutes or feet.

• 4 Fencing the first of the eight parrying positions.

  ■ [Fr.]

• 5 a special section in a cycle race.

• 6 Christian Church a service traditionally said at the first hour of the day (i.e. 6 a.m.), but now little used.

– derivatives
primeness noun.

– origin OE prīm (n.), from L. prima (hora) ‘first (hour)’, reinforced in ME by OFr. prime, from L. primus ‘first’.

Concise Oxford English Dictionary © 2008 Oxford University Press:
prime2

▶verb

• 1 make (something, especially a firearm or bomb) ready for use or action.

• 2 pour or spray liquid into (a pump) to facilitate its working.

  ■ inject extra fuel into (an engine) to facilitate starting.

  ■ (of a boiler) produce steam mixed with water.

• 3 prepare (someone) for a situation, especially by giving instructions or information.

• 4 Biology & Medicine induce a susceptibility in.

• 5 cover (a surface) with primer.

– phrases
prime the pump stimulate growth or success by supplying money.

– origin C16 (in the sense ‘fill, load’): prob. based on L. primus ‘first’.