a. 1. Sufficient for one's self without external aid or cooperation. [ 1913 Webster ]
Neglect of friends can never be proved rational till we prove the person using it omnipotent and self-sufficient, and such as can never need any mortal assistance. South. [ 1913 Webster ]
2. Having an overweening confidence in one's own abilities or worth; hence, haughty; overbearing. “A rash and self-sufficient manner.” I. Watts. [ 1913 Webster ]