noun
family background; lineage
Refers to a person's ancestry, family origin, or social standing by birth. Often used in contexts where one's pedigree is relevant, such as marriage or historical status.
彼は氏素性の知れない人物だ。
He is a person of unknown background.
結婚する前に相手の氏素性を調べる家もある。
Some families investigate the other party's lineage before marriage.
Compound of 氏 (uji, 'clan, family name') and 素性 (sujō, 'origin, background'). The exact historical derivation is uncertain, but the combination emphasizes ancestral lineage.