quinquagenary

quinquagenary [kwin-kwah-juh-ner-ee, kwing-] Word Origin noun, plural quin·quag·e·nar·ies.

1. a 50th anniversary.

Origin of quinquagenary 1580–90; Latin quīnquāgēnārius containing fifty, equivalent to quīnquāgēn(ī) fifty each + -ārius -ary