(1):

(n.) One who, or that which, pricks; a pointed instrument; a sharp point; a prickle.

(2):

(n.) A priming wire; a priming needle, - used in blasting and gunnery.

(3):

(n.) One who spurs forward; a light horseman.

(4):

(n.) A small marline spike having generally a wooden handle, - used in sailmaking.