Social entrepreneurship has recently captured the imagination of researchers and policy-makers. It promises an altruistic form of capitalism that connects enterprise with benevolence. Unfortunately there is no generally accepted definition of it, partly because there is no consensus on the definition of entrepreneurship either. Without a definition of social entrepreneurship it is impossible to research or develop policy measures for it. We propose a plausible definition that captures the way in which it may be altruistic and provide taxonomy of forms of it illustrated by Asian cases.