Exercise  —n. 1 activity requiring physical effort, done to sustain or improve health. 2 mental or spiritual activity, esp. As practice to develop a faculty. 3 task devised as exercise. 4 a use or application of a mental faculty, right, etc. B practice of an ability, quality, etc. 5 (often in pl.) Military drill or manoeuvres. —v. (-sing) 1 use or apply (a faculty, right, etc.). 2 perform (a function). 3 a take (esp. Physical) exercise. B provide (an animal) with exercise. 4 a tax the powers of. B perplex, worry. [latin exerceo keep busy]