compound adjectival word-forming element of Latin origin, attached to verb stems and expressing intensity of action: "given to, inclined to, abounding in," or expressing intensity of physical or mental action, from Latin -aci- (nominative -ax, accusative -acem), noun ending used with verbal stems (see -acea), + -ous. The accompanying nouns are formed in -acity.
Entries linking to -acious
-acea
word-forming element in Modern Latin making names for orders and classes in zoology (Crustacea, Cetacea, etc.), from Latin -acea, neuter plural of -aceus "belonging to, of the nature of" (enlarged from adjectival suffix -ax, genitive -acis).
The names are thus formally adjectives, Latin animalia "animals" (a neuter plural noun) being understood. Thus Crustacea "shellfish" are *crustacea animalia "crusty animals."
In botany, the suffix is -aceae, from the fem. plural of -aceus, forming orders or families of plants (Rosaceae, etc.) with a presumed plantae "plants," which is a fem. plural.
-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."
predacious adj.
also predaceous, "living by prey, disposed to prey or plunder, predatory," 1713, from stem of predation (Latin praedari) + -acious.