Expressions (phrases, clauses, etc.), Godan verb with 'mu' ending
to wait for a good opportunity; to come down on the right side of the fence; to see which way the cat jumps; to wait and see at Horagatoge
Proverb
Also written 洞が峠を決め込む【ほらがとうげをきめこむ】、洞ヶ峠をきめこむ【ほらがとうげをきめこむ】、洞が峠をきめこむ【ほらがとうげをきめこむ】