adjective not probable; unlikely to be true or to happen: Rain is improbable tonight.
Origin: 1590–1600; <
Latin improbābilis. See im-2, probable Related formsim·prob·a·bly, adverb
im·prob·a·ble·ness, noun
su·per·im·prob·a·ble, adjective
su·per·im·prob·a·ble·ness, noun
su·per·im·prob·a·b·ly, adverb
Synonyms
questionable, doubtful, implausible.