O.E. genog, a common Germanic formation (cf. O.N. gnogr, O.Fris. enoch, Goth. ganohs, Ger. genug), from ge- "with, together" (also a participial, collective, intensive, or perfective prefix) + root -nah, from PIE *nak- "reach, attain" (cf. Skt. asnoti "reaches," Hittite ninikzi "lifts, raises," Lith. nesti "to bear, carry," L. nancisci "to obtain"). The most prominent among the surviving examples of O.E. ge-, the equivalent of L. com- and Mod.Ger. ge-, from PIE *kom- "beside, near, by, with." Understated sense of have had enough "have had too much" was in O.E. (which relied heavily on double negatives and understatement). Colloquial 'nough said is attested from 1839.