Definition of "oppugner"

Revenge and Malice were as two violent oppugners on the one ſide, but Honeſty, Religion, Feare of God, with-held him on the other.

1621, Democritus Junior [pseudonym; Robert Burton], “Of the Will”, in The Anatomy of Melancholy, […], Oxford, Oxfordshire: Printed by John Lichfield and Iames Short, for Henry Cripps, partition 1, section 1, member 2, subsection 11, page 44

Dennis, the fiercest oppugner of puns in ancient or modern times, professes himself highly tickled with the “a stick” chiming to “ecclesiastic”.

1833, Elia [pseudonym; Charles Lamb], “[Popular Fallacies.] VIII. That Verbal Allusions Are Not Wit, Because They Will Not Bear a Translation.”, in The Last Essays of Elia. […], London: Edward Moxon, […], pages 239–240