unlikely

(a) not likely to be true or to occur or to have occurred
- legislation on the question is highly unlikely
- an improbable event
improbable,
(a) 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
(s) having a probability too low to inspire belief improbable, unbelievable, unconvincing,

improbable unbelievable unconvincing

probable likely