Old English oferdon "to do too much, be excessive or immoderate, exceed the proper limit," also in late Old English transitive, "to do (something) to excess," from ofer (see over) + don (see do (v.)). A common Germanic formation (compare Old High German ubartuan). Meaning "to overtax, exhaust, fatigue by too much action" (especially in phrase to overdo it) is attested from 1817. Of food, "to cook too long," is by 1680s (implied in past-participle adjective overdone).