To approve, encourage, and support (an action or a plan of action); urge and help on.
To urge, encourage, or help (a person): abetted the thief in robbing the bank.
[Middle English abetten, from Old French abeter, to entice : a-, to (from Latin ad-; see ad-) + beter, to bait; see bheid- in Indo-European roots.] a·bet'ment n., a·bet'tor, a·bet'ter n.