The Collaborative International Dictionary of English v.0.48:
Fabianism \Fabianism\ n. the principles and beliefs of or similar to those of the Fabian Society, advocating socialism to be established by gradual reforms within the law. [British] [WordNet 1.5]WordNet (r) 3.0 (2006):
Fabianism n 1: socialism to be established by gradual reforms within the law