"quality of being exact, accuracy, particularity," 1734, from French exactitude (17c.), from exact, from Latin exactus (see exact (adj.)).
late 14c., exaccioun, "action of demanding payment; imposition, requisitioning" of taxes, etc., from Old French exaccion and directly from Latin exactionem (nominative exactio) "a driving out; supervision; exaction; a tax, tribute, impost," noun of action from past-participle stem of exigere (see exact (adj.)). Meaning "a tax, tribute, toll, fee," etc. is from mid-15c.
Proto-Indo-European root meaning "to drive, draw out or forth, move."
It forms all or part of: act; action; active; actor; actual; actuary; actuate; agency; agenda; agent; agile; agitation; agony; ambagious; ambassador; ambiguous; anagogical; antagonize; apagoge; assay; Auriga; auto-da-fe; axiom; cache; castigate; coagulate; cogent; cogitation; counteract; demagogue; embassy; epact; essay; exact; exacta; examine; exigency; exiguous; fumigation; glucagon; hypnagogic; interact; intransigent; isagoge; litigate; litigation; mitigate; mystagogue; navigate; objurgate; pedagogue; plutogogue; prodigal; protagonist; purge; react; redact; retroactive; squat; strategy; synagogue; transact; transaction; variegate.
It is the hypothetical source of/evidence for its existence is provided by: Greek agein "to lead, guide, drive, carry off," agon "assembly, contest in the games," agōgos "leader," axios "worth, worthy, weighing as much;" Sanskrit ajati "drives," ajirah "moving, active;" Latin actus "a doing; a driving, impulse, a setting in motion; a part in a play;" agere "to set in motion, drive, drive forward," hence "to do, perform," agilis "nimble, quick;" Old Norse aka "to drive;" Middle Irish ag "battle."
