Word Origin & History
cousin1160, from O.Fr. cosin, from L. consobrinus "mother's sister's child," from com- "together" + sobrinus (earlier *sosrinos) "cousin on mother's side," from soror (gen. sororis) "sister." Used familiarly as a term of address since 1430, especially in Cornwall. Your first cousin (also cousin-german) is
the son or daughter of an uncle or aunt; your children and your first cousin's are second cousins to one another; to you, your first cousin's children are first cousin once removed. Phrase kissing cousin is Southern U.S. expression, 1940s, denoting "those close enough to be kissed in salutation;" Kentish cousin (1796) is an old British term for "distant relative."