Refers to a person who has lost in competition, life, or social standing. Often carries a pitiful or contemptuous nuance, like a 'beaten dog'. Can also be used for someone who is habitually unsuccessful.
Slang, derogatory. Popularized by the book '負け犬の遠吠え' (The Howl of the Loser Dog). Refers to an unmarried, childless woman over 30, implying she has 'lost' in the societal game of marriage and family.
