I
n.
1) to engage in, go in for ~
2) to do ~s
3) hard, strenuous, vigorous; regular ~
4) (an) aerobic; flexibility; isometric; relaxation; setting-up; warming-up ~
5) physical ~
6) a form of ~ (brisk walking is an excellent form of aerobic ~)
7) ( fig .) an ~ in (an ~ in futility)
II
v. to ~ hard, strenuously, vigorously