Noun, Suru verb, Transitive verb
waiting to see one's opponent's move before doing anything (e.g. as a disallowed act in rock, paper, scissors)
「じゃんけんね」「ぐー」「ちょ・・パー」「後出しかよ!」"Rock-paper-scissors, OK?" "Rock." "Sciss... paper." "You cheated!" bringing something up after the fact; revealing something afterwards; holding back until the last minute
Also written 後だし【あとだし】