transaction (n.)

1874, "uncompromising, refusing to agree or come to understanding," (used of extreme political factions or parties), from French intransigeant (18c.), from Spanish los intransigentes, literally "those not coming to agreement," name for extreme left in the Spanish Cortes and the extreme republicans of the 1870s, from in- "not" (see in- (1)) + transigente "compromising," from Latin transigentem (nominative transigens), present participle of transigere "come to an agreement, accomplish, to carry through" (see transaction). It acquired its generalized sense in French. As a noun in English from 1879.

1580s, intransitive, "conduct, arrange, settle;" 1630s transitive, "carry through, perform, manage, do;" a back-formation from transaction or else from Latin transactus, past participle of transigere "accomplish, bring to an end, settle," etymologically "to drive through." This is a compound of trans "across, beyond; through" (see trans-) + agere "set in motion, drive, drive forward," hence "do, perform" (from PIE root *ag- "to drive, draw out or forth, move"). Related: Transacted; transacting; transactor.