ex·er·cise 
(ĕksər-sīz′)
(ĕksər-sīz′)n.
1.
a. Activity that requires physical or mental exertion, especially when performed to develop or maintain fitness: walks every day for exercise.
b. A specific activity performed to develop or maintain fitness or a skill: sit-ups and other exercises; a piano exercise.
2.
a. The active use or application of something: the exercise of good judgment.
b. The discharge of a duty, function, or office.
3. An activity having a specified aspect: an undertaking that was an exercise in futility.
4. A military maneuver or training activity.
5. exercises A ceremony that includes speeches, presentations, and other activities: graduation exercises.
v. ex·er·cised, ex·er·cis·ing, ex·er·cis·es
v.tr.
1.
a. To subject to practice or exertion in order to train, strengthen, or develop: exercise the back muscles; exercise the memory.
b. To put through exercises: exercise a platoon. See Synonyms at practice.
2.
a. To make active use of; employ, apply, or exert: exercise restraint; exercise control.
b. To discharge (duties, for example).
3.
a. To carry out the functions of: exercise the role of disciplinarian.
b. To execute the terms of (a stock option, for example).
4. To alarm, worry, or anger; upset: an injustice that exercised the whole community.
v.intr.
To engage in exercise.
[Middle English, from Old French exercice, from Latin exercitium, from exercitus, past participle of exercēre, to exercise : ex-, ex- + arcēre, to restrain.]
exer·cis′a·ble adj.