erosive (adj.)

1610s, "gnaw or eat away" (transitive), a back-formation from erosion, or else from French éroder, from Latin erodere "to gnaw away, consume," from assimilated form of ex "away" (see ex-) + rodere "to gnaw" (see rodent). Intransitive sense "become worn away" is by 1905. Related: Eroded; eroding. Originally of acids, ulcers, etc.; geological sense is from 1830.

word-forming element making adjectives from verbs, meaning "pertaining to, tending to; doing, serving to do," in some cases from Old French -if, but usually directly from Latin adjectival suffix -ivus (source also of Italian and Spanish -ivo). In some words borrowed from French at an early date it has been reduced to -y (as in hasty, tardy).