Word Origin & History
againO.E. ongean "toward, opposite, against," from on "on" + -gegn "against, toward," for a sense of "lined up facing, opposite," and "in the opposite direction, returning." For -gegn, cf. O.N. gegn "straight, direct," Dan. igen "against," O.Fris. jen, O.H.G. gegin, Ger. gegen "against, toward," Ger. entgegen
"against, in opposition to." In O.E., eft was the main word for "again," but this often was strengthened by ongean, which became the principal word by 13c. Norse influence is responsible for the hard -g-. Differentiated from against 16c. in southern writers, again becoming an adverb only, and against took over as prep. and conjunction, but again clung to all senses in northern and Scottish dialect.