Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Ŏlympĭŏnīces, ae, m., = Ὀλυμπιονίκης, a victor at the Olympic games: Atyanas pugil, Olympionices, Cic. Fl. 13, 31; id. Tusc. 1, 46, 111.
As adj.: Olympionicarum equarum, Col. 3, 9, 5.