As I was lifting myself up for the fiftieth time, he said, “Now get in the water and make a sugar cookie.”
He even bought a convertible sports car for his fiftieth birthday.
Old English fiftigoða; see fifty + -th (1). Cf. Old Norse fimmtugande, and, with a different suffix, Old Frisian fiftichsta, Dutch vijftigste, Old High German fimfzugsto, German fünfzigste.