Early 19th century; earliest use found in Nathan Drake (1766–1836), essayist and physician. From classical Latin masculus + -arity, perhaps after muscularity, or perhaps a blend of the two words.
Definition of mascularity in US English:
mascularity
nounˌmaskjʊˈlarɪti
rare
Masculinity.
Origin
Early 19th century; earliest use found in Nathan Drake (1766–1836), essayist and physician. From classical Latin masculus + -arity, perhaps after muscularity, or perhaps a blend of the two words.