To assist and promote or encourage something or someone. The pairing of these nearly synonymous verbs, always in this order, comes from criminal law, where it denotes helping, facilitating and promoting the commission of a crime. The verbs themselves are quite old, aid dating from about 1400 and abet from about 1300. Although the term still is principally used in relation to criminal actions, it gradually crept into more general speech, as in “The influx of Canada geese on the golf course, aided and abetted by people feeding them . . .”