(music) A group of four musicians who sing barbershop music. Usually contains high and lead tenors, baritone and bass.

of three fourths of the usual dimension / (of a portrait) with the subject turned slightly away from a frontal view

(rugby) A player positioned between the half-backs and the full-backs (properly a three-quarter back) / (only in singular) A fraction with three of four equal parts (=75 %)

Three of four equal parts (3/4, ¾, 0.75).

A wooden staff of an approximate length between 2 and 2.5 meters, sometimes tipped with iron, used as a weapon in rural England during the Early Modern period.

the mining of gold-bearing quartz

(geology) A metamorphosed schist composed mostly of quartz with some mica and/or tourmaline.

a diamond-shaped pane of glass designed to be set in leads

One who quarantines. / One who is quarantined.

A belt connecting pulleys whose axles are at right angles; a quarter turn belt.