godan verb (-ku), transitive verb
Used for breaking or knocking a piece off something by striking it. Often implies a forceful, chipping action.
石を打ち欠いて形を整える。
Break off pieces of stone to shape it.
彼はハンマーで壁の角を打
He knocked off the corner of the wall with a hammer.
godan verb (-ku), transitive verb
create a false eye by sacrificing a stone (go)
Technical go term: to intentionally sacrifice a stone to make a false eye, disrupting the opponent's shape.
相手の眼を打ち欠いて、生きを奪う手筋だ。
It's a technique to create a false eye by sacrificing a stone and take away the opponent's life.