|a pulsation of the heart, including one complete systole and diastole|
|an innate mechanism of the body that regulates its rhythmic and periodic cycles|
|voluntary (ˈvɒləntərɪ, -trɪ)|
|1.||performed, undertaken, or brought about by free choice, willingly, or without being asked: a voluntary donation|
|2.||(of persons) serving or acting in a specified function of one's own accord and without compulsion or promise of remuneration: a voluntary social worker|
|3.||done by, composed of, or functioning with the aid of volunteers: a voluntary association|
|4.||endowed with, exercising, or having the faculty of willing: a voluntary agent|
|5.||arising from natural impulse; spontaneous: voluntary laughter|
|a. acting or done without legal obligation, compulsion, or persuasion|
|b. made without payment or recompense in any form: a voluntary conveyance|
|7.||(of the muscles of the limbs, neck, etc) having their action controlled by the will|
|8.||maintained or provided by the voluntary actions or contributions of individuals and not by the state: voluntary schools; the voluntary system|
|—n , -taries|
|9.||music a composition or improvisation, usually for organ, played at the beginning or end of a church service|
|10.||work done without compulsion|
|11.||obsolete a volunteer, esp in an army|
|[C14: from Latin voluntārius, from voluntās will, from velle to wish]|
voluntary vol·un·tar·y (vŏl'ən-těr'ē)
Arising from or acting on one's own free will.
Normally controlled by or subject to individual volition, as of respiration.
Capable of making choices; having the faculty of will.