exercise

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Activity that requires physical or mental exertion, especially when performed to develop or maintain fitness.
• noun A specific activity performed to develop or maintain fitness or a skill.
• noun The active use or application of something.
• noun The discharge of a duty, function, or office.
• noun An activity having a specified aspect.
• noun A military maneuver or training activity.
• noun A ceremony that includes speeches, presentations, and other activities.
• intransitive verb To subject to practice or exertion in order to train, strengthen, or develop.
• intransitive verb To put through exercises: synonym: practice.
• intransitive verb To make active use of; employ, apply, or exert.
• intransitive verb To discharge (duties, for example).
• intransitive verb To carry out the functions of.
• intransitive verb To execute the terms of (a stock option, for example).
• intransitive verb To alarm, worry, or anger; upset.
• intransitive verb To engage in exercise.

from The Century Dictionary.

• noun A carrying on or out in action; active performance or fulfilment; a physical or mental doing or practising: used of the continued performance of the functions, or observance of the requirements, of the subject of the action: as, the exercise of an art, a trade, or an office; the exercise of religion, of patience, etc.
• noun Voluntary action of the body or mind; exertion of any faculty; practice in the employment of the physical or mental powers: used absolutely, or with reference to the reflex effect of the action upon the actor: as, to take exercise in the open air; corporeal or spiritual exercise; violent, hurtful, pleasurable, or healthful exercise.
• noun A specific mode or employment of activity; an exertion of one or more of the physical or mental powers; practice in the use of a faculty or the faculties, as for the attainment of skill or facility, the accomplishment of a purpose, or the like: as, an exercise in horsemanship; exercises of the memory; outdoor exercises.
• noun A disciplinary task or formulary; something done or to be done for the attainment of proficiency or skill; a set or prescribed performance for improvement, or an example or study for improving practice: as, school exercises; an exercise in composition or music; exercises for the piano or violin.
• noun A performance or procedure in general; a definite or formal act for a purpose; specifically, a feature or part of a program or round of proceedings: as, the exercises of a college commencement, or of a public meeting; graduating exercises.
• noun A spiritual or religious action or effort; an act or procedure of devotion or for spiritual improvement; religious worship, exhortation, or the like.
• noun Specifically— Among the Puritans, a church service or week-day sermon: still occasionally used.
• noun Family worship. [Scotch.]
• noun Formerly, in Scotland, the critical explication of a passage of Scripture, at a meeting of presbytery, by a teaching presbyter, succeeded by a specification of the doctrines contained in it by another, both discourses being judged of, and censured, if necessary, by the rest of the brethren.
• noun Formerly, also, the presbytery.
• noun A disciplinary spiritual experience or trial; spiritual agitation.
• To put in practice; carry out in action; perform the functions or duties of: as, to exercise authority or power; to exercise an office.
• To put in action; employ actively; set or keep in a state of activity; make use of in act or procedure: as, to exercise the body, the voice, etc.; to exercise the reason or judgment; exercise your skill in this work.
• To train or discipline by means of exertion or practice; put or keep in practice; make, or cause to make, specific trials: as, to exercise one's self in music; to exercise troops.
• To give mental occupation or exercise to; cause to think earnestly or anxiously; make uneasy: as, he is exercised about his spiritual state.
• To impart as an effect; put forth as a result or consequence; communicate; exert.
• Synonyms To apply.
• To drill.
• To try, afflict, pain, annoy.
• To use action or exertion; exert one's self; take exercise: as, to exercise for health or amusement.
• To conduct a religious exercise, as the exposition of Scripture.

from the GNU version of the Collaborative International Dictionary of English.

• noun The act of exercising; a setting in action or practicing; employment in the proper mode of activity; exertion; application; use; habitual activity; occupation, in general; practice.
• noun Exertion for the sake of training or improvement whether physical, intellectual, or moral; practice to acquire skill, knowledge, virtue, perfectness, grace, etc.
• noun Bodily exertion for the sake of keeping the organs and functions in a healthy state; hygienic activity.
• noun The performance of an office, a ceremony, or a religious duty.
• noun That which is done for the sake of exercising, practicing, training, or promoting skill, health, mental, improvement, moral discipline, etc.; that which is assigned or prescribed for such ends; hence, a disquisition; a lesson; a task
• noun That which gives practice; a trial; a test.
• noun (Med.) a deposit of bony matter in the soft tissues, produced by pressure or exertion.
• intransitive verb To exercise one's self, as under military training; to drill; to take exercise; to use action or exertion; to practice gymnastics.
• transitive verb To set in action; to cause to act, move, or make exertion; to give employment to; to put in action habitually or constantly; to school or train; to exert repeatedly; to busy.