The term enabler has come to mean someone who doesn't turn a blind eye to another's poor choices, bad habits or negative behaviour.

An enabler, by their response actually encourages and/or supports the poor choices by directly or indirectly rewarding the person who is acting out (addictions, aggression, inaction). Enablers aren't bad people. Usually their response is born out of compassion and sympathy. Their fear is often of the guilt that may result from saying "no", and then seeing what they perceive as "suffering' by that other person. One cure is recognizing personal rights and boundaries. In other words, be relatively o.k. with saying "no" and not supporting the bad behaviour. Know too that by making such a change in your response may result in an "upping of the ante", an escalation of negative behaviour on the part of the other person (like a tantrum). Know your rights, know how to assert your rights and be strong. It's for your own good and often ultimately for the good of the other person as well.