adj ·Moderate ·College level

Definitions

Adjective

1. 1
   Not likely to be true.

   "It's highly improbable that aliens abducted you."

2. 2
   Not likely to happen.

   "Due to the loss of power, it is improbable that we will begin on time."

Adjective

1. 1
   too improbable to admit of belief wordnet
2. 2
   not likely to be true or to occur or to have occurred wordnet
3. 3
   having a probability too low to inspire belief wordnet

Synonyms

All synonyms

doubtfulunbelievableunlikelyabsurdcalculablecrazy

Antonyms

All antonyms

probable

Example

More examples

"Your explanation won't wash; it's too improbable to be true."

Etymology

Borrowed from Latin improbābilis. By surface analysis, im- + probable.

Related phrases

statistically improbable phrase

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.