Synonyms for Unlikelihood:

n.

attribute (noun)
unlikeliness.
dark horse (noun)
improbability.
hopelessness (noun)
impossibility.
improbability (noun)
implausibility, doubtfulness, incredibility, improbability.
unlikelihood (noun)
unlikeliness.

Other synonyms:

uncertainty. Other relevant words:
inconceivability, remote possibility, uncertainty, impossibility, unlikeliness.

Usage examples for unlikelihood

  1. The extremes are the best; the former for their intrinsic value, the latter from their unlikelihood to mislead. – The Ethnology of the British Islands by Robert Gordon Latham
  2. I don't care what people accuse me of, but to marry a girl like Nina Randolph- even assuming the unlikelihood that she'd have me- would be a fatal mistake, unless I had a fortune to match her own. – The Title Market by Emily Post