A follower or adherent of Pyrrho of Elis; an advocate of Pyrrhonism; a sceptic.
Also with lower-case initial. Of, relating to, or characteristic of Pyrrho or Pyrrhonism; adhering to the sceptical doctrines of Pyrrho; sceptical.
Mid 16th century. From classical Latin Pyrrhōn-, Pyrrhō (ancient Greek Πύρρων), the name of Pyrrho of Elis (300 b.c.), founder of the first school of Greek sceptic philosophy + -ian, probably after classical Latin pyrrhōnius, adjective and noun.