Probably from the same as skeuos; to elaborate, i.e. (figuratively) train (by implication, strive) -- exercise.
see GREEK skeuos
1. to form by art, to adorn; in Homer.
2. to exercise (oneself), take pains, labor, strive; followed by an infinitive (as in Xenophon, mem. 2, 1, 6; Cyril 5, 5, 12, etc.): Acts 24:16.