Entry from British & World English dictionary
Definition of optimate in English:
noun (plural optimates /ɒptɪˈmeɪtiːz/)
1A member of the patrician order in ancient Rome: he privately urged Cicero to determined action on behalf of the optimates
late 16th century: from Latin plural optimates 'aristocrats', noun use of optimas 'aristocratic', from optimus 'best'.