"capable of endurance," 1752, from Latin fortitudinem (nominative fortitudo) "strength, firmness" (see fortitude) + -ous. Related: Fortitudinously.
Entries linking to fortitudinous
fortitude n.
late 14c., "moral strength (as a cardinal virtue); courage," from Latin fortitudo "strength, force, firmness, manliness," from fortis "strong, brave" (see fort). From early 15c. as "physical strength."
-ous
word-forming element making adjectives from nouns, meaning "having, full of, having to do with, doing, inclined to," from Old French -ous, -eux, from Latin -osus (compare -ose (1)). In chemistry, "having a lower valence than forms expressed in -ic."