Early 19th century; earliest use found in Samuel Taylor Coleridge (1772–1834), poet, critic, and philosopher. Either from affectible + -ity, or from affect + -ibility, perhaps after French affectibilité.
Definition of affectibility in US English:
affectibility
nounəˌfɛktəˈbɪlɪti
= affectability.
Origin
Early 19th century; earliest use found in Samuel Taylor Coleridge (1772–1834), poet, critic, and philosopher. Either from affectible + -ity, or from affect + -ibility, perhaps after French affectibilité.