熟习

熟习	shú xí	to understand profoundly / well-versed / skillful / practiced / to have the knack
熟	shú	ripe; mature / thoroughly cooked; done / familiar; acquainted / experienced; skilled / (of sleep etc) deep; profound / also pr. [shou2]
习	Xí	surname Xi
习	xí	(bound form) to practice / to study / habit / custom