1. not likely to happen or be true

Examples

• It seems improbable that it will rain today given the clear skies.
• The witness told an improbable story about seeing aliens.
• Against all improbable odds, the underdog team won the championship.
• Her excuse for being late was highly improbable.
• The detective found the suspect’s alibi improbable.
• It’s improbable that he finished the entire project in one day.