Plug

n. [D. plug, Dan. plök, plug, Sw. plugg, pligg, L. Ger. plugge, plukk, N. H. Ger. pflock.]

1. Any piece of wood or other substance used to stop a hole; a stopple.
2. The foil or other matter used by a dentist to fill the cavity in a tooth. [U. S.]
3. A flat, oblong cake of pressed tobacco moistened with molasses. [U. S.] Bartlett.
4. A gentleman's silk hat; — so called from its cylindrical form. [Colloq. and low.]

Hawse-plug (Naut.), a plug to stop a hawse-hole. — Plug-center-bit, a center bit ending in a small cylinder instead of a point, so as to follow and enlarge a hole previously made, or to form a countersink around it. — Shot-plug, a plug to stop a breach made by a cannon-ball in the side of a ship.