n. & v.
n. 1 an instrument for measuring time, driven mechanically or electrically and indicating hours, minutes, etc., by hands on a dial or by displayed figures. 2 a any measuring device resembling a clock. b colloq. a speedometer, taximeter, or stopwatch. 3 time taken as an element in competitive sports etc. (ran against the clock). 4 Brit. sl. a person's face. 5 a downy seed-head, esp. that of a dandelion.
v.tr. 1 colloq. a (often foll. by up) attain or register (a stated time, distance, or speed, esp. in a race). b time (a race) with a stopwatch. 2 Brit. sl. hit, esp. on the head. clock golf a game in which a golf ball is putted into a hole from successive points in a circle. clock in (or on) register one's arrival at work, esp. by means of an automatic recording clock. clock off (or out) register one's departure similarly. clock radio a combined radio and alarm clock. round the clock all day and (usu.) night. watch the clock = CLOCK-WATCH.
[ ME f. MDu., MLG klocke f. med.L clocca bell, perh. f. Celt. ]