improbable adj.
VERBS appear, be, look, seem, sound | become | make sth These new facts make the theory improbable.
ADV. extremely, highly, very, wildly a wildly improbable idea | completely, quite | not altogether | fairly, rather, slightly | inherently, intrinsically There is nothing inherently improbable in the idea.
You can also check other dicts: improbable (English, 中文解释 ), wordnet sense, Collins Definition