Prim"ing (?), n. 1. The powder or other combustible used to communicate fire to a charge of gunpowder, as in a firearm.

2. (Paint.) The first coating of color, size, or the like, laid on canvas, or on a building, or other surface.

3. (Steam Eng.) The carrying over of water, with the steam, from the boiler, as into the cylinder.

Priming of the tide. See Lag of the tide, under 2d Lag. -- Priming tube, a small pipe, filled with a combustible composition for firing cannon. -- Priming valve(Steam Eng.), a spring safety valve applied to the cylinder of a steam engine for discharging water carried into the cylinder by priming. -- Priming wire, a pointed wire used to penetrate the vent of a piece, for piercing the cartridge before priming.