I-adjective (keiyoushi)
frustrated (over a failure, humiliation or injustice); annoyed; chagrined; (bitterly) disappointed; bitter; vexed; frustrating; annoying; regrettable
監督はチームをトーナメント優勝に今一歩という所までもっていったのに悔しいことだった。It was annoying, as the manager took his team to a near-miss in the tournament.
Also written 口惜しい【くやしい】