(nautical) A petty officer who assists the gunner.

(geology) A form of quartz with an unusual microscopic structure that has been deformed along planes inside the crystal by the application of extremely high pressure at moderate temperature; generally produced only by hypervelocity impact events, lightning strikes, and nuclear explosions.

(time) quarter of an hour; period of time equal to 15 minutes; a quarter.

Quartz occurring as gangue in a vein.

(humorous, neologism) A martini-style cocktail popular amongst people in COVID-19 lockdown.

(card games) The game of rouge et noir.

(military) No mercy; no sparing the life of a captured opponent.

plural of quarter tone

An automaton, on a clock, that strikes a bell every quarter hour

Less common spelling of one-quarter