Prime, v. t. [imp. & p. p.Primed (?); p. pr. & vb. n.Priming.] [From Prime, a.] 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. Thackeray.
4. To trim or prune, as trees.
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.