cousin (English)

Where does "cousin" come from?

The word 'cousin' traces its roots back to the Proto-Indo-European term *swésōr, meaning 'sister,' reflecting the concept of a woman 'of one's own blood.' This evolved into the Latin 'cōnsobrīnus,' which specifically denoted a maternal cousin before passing into Old French as 'cosin' and 'cosine.' Over time, the term migrated into Middle English, expanding from its original meaning of a close blood relative to encompass a wide range of kin, social titles, and colloquial associations.

Full etymology tree

cousin (English), 'Chiefly with a qualifying word: Any relation (especially a distant one) who is not a direct ancestor or descendant but part of a person's extended family; a kinsman or kinswoman.'
- inherited cosin (Middle English), 'alternative form of cosyn'
  - inherited cosin (Anglo-Norman)
    - inherited cosin (Old French), 'cousin'
      - inherited cōnsobrīnus (Latin), 'a first cousin, cousin-german'
        derived con- (Latin), 'Used in compounds to indicate a being or bringing together of several objects'
        derived sobrīnus (Latin), 'sororal nephew'
        derived *swezrīnos (Proto-Italic), 'of/belonging to the sister'
        derived *swezōr (Proto-Italic), 'sister'
        inherited *swésōr (Proto-Indo-European), 'sister'
        derived *swé (Proto-Indo-European), 'self (reflexive pronoun)'
        derived *h₁ésh₂r̥ (Proto-Indo-European), 'blood'
        affix *-īnos (Proto-Italic), 'of/belonging to'

Direct ancestors

Updated July 2026

Etymology data from Wiktionary, CC BY-SA 4.0 · About Miraris