WordNet records no synonym and no antonym for votary. It is the only member of each of its synsets, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
one bound by vows to a religion or life of worship or service
“monasteries of votaries”
a priest or priestess (or consecrated worshipper) in a non-Christian religion or cult
“a votary of Aphrodite”
Synonyms, antonyms and the broader and narrower relations for votary come from Princeton University’s WordNet. Full sources and licences.
a devoted (almost religiously so) adherent of a cause or person or activity
“the cultured votary of science”