prevaricator n.

c. 1400, prevaricatour, "transgressor of the law," a sense now obsolete, from Old French prevaricator and directly from Latin praevaricator "sham accuser; unfaithful advocate," agent noun from past participle stem of praevaricari "to make a sham accusation, deviate" (from the path of duty), literally "walk crookedly" (see prevaricate). "At Cambridge Univ: An orator who made a jocose or satirical speech at Commencement" [OED] (1610s). Fem. form prevaricatrice is attested from c. 1500. Main modern meaning "one who acts or speaks so as to evade the strict truth" is from 1640s.