litigation n.

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."

c. 1300, "make a formal declaration in court;" mid-14c., "pronounce positively, claim as true," with or without proof; it has the form of one French verb and the meaning of another. The form is Anglo-French aleger, Old French eslegier "to clear at law" (from a compound of Latin ex "out of;" see ex- + litigare "bring suit" (see litigation).

However eslegier meant "acquit, clear of charges in a lawsuit," and the Middle English word somehow acquired the meaning of French alléguer, from Latin allegare/adlegare "send for, bring forth, name, produce in evidence, send on business," from ad "to" (see ad-) + legare "to depute, send" (see legate). Related: Alleged; alleging.