1.Definition: has little chance of being the case or coming about

"An unlikely story", "An unlikely candidate for reelection", "A butcher is unlikely to preach vegetarianism"

2.Definition: having a probability too low to inspire belief

Related Adjective(s):improbable, unbelievable, unconvincing

3.Definition: not likely to be true or to occur or to have occurred

"Legislation on the question is highly unlikely"

Related Adjective(s):improbable