出典:Wiktionary
From Latin quinquāgēnārius (“containing 50”) + -an, either directly or via French quinquagénaire, from Latin quīnquāgēnī (“50 each”) + -ārius (“-ary”), from quīnquāgintā (“five tens, fifty”). Cognate with quinquagenary.
quinquagenarian (複数形 quinquagenarians)
quinquagenarian (not comparable)