γυμνάζω

But strong meat belongeth to them that are of full age, even those who by reason of use have their senses exercised to discern both good and evil.

Now no chastening for the present seemeth to be joyous, but grievous: nevertheless afterward it yieldeth the peaceable fruit of righteousness unto them which are exercised thereby.

But refuse profane and old wives' fables, and exercise thyself rather unto godliness.

Having eyes full of adultery, and that cannot cease from sin; beguiling unstable souls: an heart they have exercised with covetous practices; cursed children: