2. (noun)possibility, possibleness capability of existing or happening or beingtrue "there is a possibility that his sense of smell has been impaired"
3. (noun)hypothesis, possibility, theory a tentative insight into 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"
4. (noun)possibility, possible action, opening a possiblealternative "bankruptcy is always a possibility"