necessarian UK /ˌnɛsəˈsɛəɹi.ən/US /ˌnɛsəˈsɛɹi.ən/ noun1 •An adherent of necessarianism; an advocate of the doctrine of necessity.But neither you nor myself, necessarian as I am, can pretend to this degree of perfection. — 1832 formsNecessarians · necessarians