Pentrois
Describing pengenders/penugenders/penegender/paenegenders/paenugenders/paengenders, paragenders, quasi-genders, -jux-/-prox(imal)- genders, perigenders and almogenders. Who are proximal to certain gender in the spectrum.
Based on penultrois/penultimatrois, pen- meaning "almost, nearly", just as in penumbra and peninsula. Alternative words: penutrois, paentrois, paenutrois, paenetrois, penetrois, peritrois, paratrois, pertrois, partrois, proxitrois, pæntrois, pænutrois.
Ultimatrois
Or ultrois. Conoting ultimate genders or gender ultimacy, your final/last gender (previous/prior/recent/subsequent) or its extremity/maximum. Your foremost, furthest gender (innermost/utmost/midmost/topmost), but it's ultimary not citimary/citrois, ulterior(ity) not citerior(ity) [citi-/citer-/citra- is the opposite of ultra-/ulti-/ulter-].
Ultimarity could be an (ant)arity that goes beyond limits or is subsequent/ends somewhere. Uls denotes beyond, just as extr(a)-/exter-.
Paenultrois/paenultimatrois can result in (pro/pre)antepenultrois/(pro/pre)antepaenultrois/(pro/pre)antepaenultimatrois/(pro/pre)antepenultimatrois, indicating gender(s) before the penultimate one, that you may or may not have.