Mid 19th century; earliest use found in William Thackeray (1811–1863), novelist. From opine + -ant, perhaps after French opinant someone who gives an opinion in a deliberation.
Definition of opinant in US English:
opinant
nounˈɒpɪnənt
rare
A person who opines or forms an opinion.
Origin
Mid 19th century; earliest use found in William Thackeray (1811–1863), novelist. From opine + -ant, perhaps after French opinant someone who gives an opinion in a deliberation.