not wanting to admit one has lost or failed; being a sore loser; sour grapes
köken: From 負(ま)け (make, 連(れん)用(よう)形(けい) (ren'yōkei, “stem or continuative form”) of the verb 負(ま)ける (makeru, “to lose”)) + 惜(お)しみ (oshimi, 連(れん)用(よう)形(けい) (ren'yōkei, “stem or continuative form”) of the verb 惜(お)しむ (oshimu, “to resent”)).