"an unlikely story"; "an unlikely candidate for reelection"; "a butcher is unlikely to preach vegetarianism"
is similar to
highly imaginative but unlikely
"a farfetched excuse"; "an implausible explanation"
is similar to
most unlikely or unsuitable
"the last person we would have suspected"; "the last man they would have chosen for the job"
is similar to
very unlikely
"an outside chance"; "a remote possibility"; "a remote contingency"
is an attribute of
the probability of a specified outcome