勝かっ手て知しったる

expression, noun-modifying (irregular)

well aware of; know thoroughly; familiar with (and thus feel no need for restraint)

Used when someone knows a place, person, or situation so well that they act freely and without hesitation, often implying a sense of ease or lack of formality.

• 彼かれは勝かっ手て知しったる我わが家やのよう