early 14c., "corrupted, debased in character," from Old French corropt "unhealthy, corrupt; uncouth" (of language) and directly from Latin corruptus, past participle of corrumpere "to destroy; spoil," figuratively "corrupt, seduce, bribe," from assimilated form of com-, here probably an intensive prefix (see com-), + rup-, past participle stem of rumpere "to break," from a nasalized form of PIE *runp- "to break" (source also of Sanskrit rupya- "to suffer from a stomach-ache;" Old English reofan "to break, tear").
Meaning "decomposing, putrid, spoiled" is from late 14c. Sense of "changed for the worse, debased by admixture or alteration" (of language, etc.) is from late 14c. Meaning "guilty of dishonesty involving bribery" is from late 14c. Related: Corruptly; corruptness.