Obs. [a. OFr. acheson, acheison, achaison, -un occasion, cause, motive:—L. occāsiōnem occasion, n. of action f. occās- ppl. stem of occid-ĕre, f. oc- = ob- in the way of + cad-ĕre to fall. Very early refashioned in Anglo-Fr. as anchesoun, enchesoun, by form-assoc. with words in which a- stood for earlier en-, an-: see A- pref. 10, so that ENCHESOUN, ENCHEASON, became a far more common form in Eng. Also as early as 3 aphetized to CHESOUN.] Occasion, reason, purpose, motive.
c. 1330. Arthour & Merlin, 132. And all he it dede for traisoun, King to be was his achesoun.
c. 1230. Ancren Riwle, 232. Six ancheisuns beoð hwi God … wiðdrauhð him.
1297. R. Glouc., 452. Wan ich am enchesun of such pereyl.
a. 1400. Metr. Hom., 38. Bot chesoun till him fand scho nan.
