microgametophyte UK /ˌmaɪ.kɹəʊ.ɡəˈmiː.təˌfaɪt/US /ˌmaɪ.kɹoʊ.ɡəˈmi.təˌfaɪt/ noun2 •Any gametophyte that develops from a microspore. •A male gametophyte. formsmicrogametophytes