Prime, v. t. [imp. & p. p. Primed p. pr. & vb. n. Priming.]
 1. To apply priming to, as a musket or a cannon; to apply a primer to, as a metallic cartridge.
 2. To lay the first color, coating, or preparation upon (a surface), as in painting; as, to prime a canvas, a wall.
 3. To prepare; to make ready; to instruct beforehand; to post; to coach; as, to prime a witness; the boys are primed for mischief. [Colloq.]
 4. To trim or prune, as trees. [Obs. or Prov. Eng.]
 5. Math. To mark with a prime mark.
 To prime a pump, to charge a pump with water, in order to put it in working condition.