Word origin
ME
declenson < OFr
declinaison < L
declinatio, a bending aside, inflection (< pp. of
declinare: see decline): ME form infl. by assoc. with L
descensio, a descending: see descend; (sense 3) from the concept of cases as “declining” from the nominative: cf. , case
1 (sense 9
)