loserness

Noun

slang uncountable

(slang) The quality of being a loser.

Japanese Meaning

負け犬である性質、敗者気質 / 敗北感や敗者としての特徴

No amount of flashy clothes could cover the loserness that became obvious whenever he lost a game.

どれだけ派手な服を着ても、試合に負けるたびに彼の負け犬っぷりは隠せなかった。

Sense（1）

(slang) The quality of being a loser.