- allay
- O.E. alecgan "to put down, remit, give up," a Gmc. compound (cf. Goth. uslagjan, O.H.G. irleccan, Ger. erlegen), from a- "down, aside" + lecgan "to lay" (see lay). Pronunciations of early M.E. -y- and -g- were not always distinct, and the word was confused in M.E. with various senses of Romanic-derived alloy and allege, especially the latter in an obs. sense of "to lighten," from L. ad- "to" + levis (see lever).
"Amid the overlapping of meanings that thus arose, there was developed a perplexing network of uses of allay and allege, that belong entirely to no one of the original vbs., but combine the senses of two or more of them." [OED]
The double -l- is 17c., a mistaken Latinism.