1565, "zealous, eager to serve," from L. officiosus "dutiful," from officium "duty, service" (see office). Sense of "meddlesome, doing more than is asked or required" had emerged by 1600 (in officiously). An officious lie (1577) is one told to do good to another person (from
L. mendocium officiosum or Fr. mensonge officieux).