Antipope

Antipope, a pope elected by a civil power in opposition to one elected by the cardinals, or one self-elected and usurped; there were some 26 of such, first and last.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)

An`tiphon * Antipyretics
Antinomianism
Antinomy
Antin`ous
An`tioch
Anti`ochus
Anti`ope
Antip`aros
Antip`ater
Antiph`ilus
An`tiphon
Antipope
Antipyretics
Antipyrin
Antisa`na
Antise`mites
Antiseptics
Antis`thenes
Anti-Taurus
Antium
Antiva`ri
Antofagas`ta