To Regret
To Mourn, To Lament
transitive verb, godan verb
くやむ
悔やむ (くやむ) To Regret, To Mourn, To Lament
悔しい (くやしい) Regrettable, Frustrating, Vexing, Disappointing
弔う (とむらう) To Mourn For, To Hold A Memorial Service For, To Condole
嘆く (なげく) To Lament, To Grieve
憂える (うれえる) To Be Anxious, To Worry About, To Lament, To Grieve, To Be Distressed
Cool く ya や dance moves む or you might Regret it.