ex·er·cise 1 /'ek-sər-ˌsīz/ n
1: the discharge of an official function or professional occupation
2: the act or an instance of carrying out the terms of an agreement (as an option)
exercise 2 vt -cised, -cis·ing
1: to make effective in action
exercising power
2: to bring to bear
3: to implement the terms of (as an option)
ex·er·cis·able /ˌek-sər-'sī-zə-bəl, 'ek-sər-ˌsī-/ adj

Merriam-Webster’s Dictionary of Law. . 1996.

I (discharge a function) verb act, administer, carry into execution, carry on, carry out. conduct, do duty, efficere, engage in, execute, exercere, facere, officiate, perform, practice, pursue, put in motion, put into action, put into effect, put into practice, serve as, translate into action, wage associated concepts: authority exercised under the United States Constitution, exercise an option, exercise jurisdiction, exercise of judicial discretion foreign phrases:
- Cut jurisdictio data est, ea quoque concessa esse videntur, sine quibus jurisdictio explicari non potest. — To whomsoever jurisdiction is given, those things also are supposed to be granted, without which the jurisdiction cannot be exercised
- Frustra est potentia quae nunquam venit in actum. — A power is a vain one if it is never exercised
II (use) verb apply, avail oneself of, bring into play, bring to bear, draw on, employ, make use of, manipulate, operate, practice, put in action, put in practice, put to use, put to work, turn to account, utilize, wield associated concepts: exercise a right to vote, exercise an option, exercise discretion, exercise dominion, exercise due care, exercise of power III index apply (put in practice), campaign, commission (act), discipline (training), employ (make use of), endeavor, exert, exploit (make use of), labor, officiate, operate, ply, practice (train by repetition), problem, resort, transaction, undertaking (enterprise), wield, work (effort)

Burton's Legal Thesaurus. . 2006

To put into action, practice, or force; to make use of something, such as a right or option.

Dictionary from West's Encyclopedia of American Law. 2005.

To put into action, practice, or force; to make use of something, such as a right or option.

Short Dictionary of (mostly American) Legal Terms and Abbreviations.