惜しむ【おしむ】
to be frugal, to be sparing, to value, to hold dear, to regret (e.g. a loss), to feel sorry (for), to be unwilling, to be reluctant
惜敗【せきはい】
regrettable defeat, defeat by a narrow margin
惜しい【おしい】
regrettable, disappointing, unfortunate, precious, dear, valuable, too good for, deserving better, almost (but not quite), close (but no cigar)
負け惜しみ【まけおしみ】
being a poor loser, unwillingness to admit defeat, sour grapes