late 14c., "to eat away, diminish or disintegrate (something) by gradually separating small bits of it," from Old French corroder (14c.) and directly from Latin corrodere "to gnaw to bits, wear away," from assimilated form of com-, here probably an intensive prefix (see com-), + rodere "to gnaw" (possibly from an extended form of PIE root *red- "to scrape, scratch, gnaw"). Figurative use from 1630s. Related: Corroded; corroding.
