Regrettable
Frustrating, Vexing, Disappointing
い adjective
くやしい
悔やむ (くやむ) To Regret, To Mourn, To Lament
悔しい (くやしい) Regrettable, Frustrating, Vexing, Disappointing
惜しい (おしい) Regrettable, Disappointing, Precious, Dear
遺憾 (いかん) Regrettable, Unsatisfactory
詳しい (くわしい) Detailed, Expert
Cool く...yeah や...shit しい...that was Regrettable.