What is "abhorrer"

Abhorrer \Ab*hor"rer\, n. One who abhors.
--Hume.

n. 1 One who abhors. (Early 17^th century.)(R:SOED5: page=4) 2 (context historical sometimes capitalized English) A nickname given in the early 17^th century to signatories of addresses of a petition to reconvene parliament, addressed to Charles II. (Early 17^th century.)

n. a signer of a 1679 address to Charles II in which those who petitioned for the reconvening of Parliament were condemned and abhorred