capability of existing or happening or being true; "there is a possibility that his sense of smell has been impaired"
www.cogsci.princeton.edu/cgi-bin/webwn
a tentative theory about the natural world; a concept that is not yet verified but that if true would explain certain facts or phenomena; "a scientific hypothesis that survives experimental testing becomes a scientific theory"; "he proposed a fresh theory of alkalis that later was accepted in chemical practices"
www.cogsci.princeton.edu/cgi-bin/webwn