Something or somebody considered unlikely.
"The candidate was an unlikely winner, yet he secured victory on election night."
In plain English: There is no noun form of unlikely because it is only an adjective used to describe something that has a low chance of happening.
"His unlikely victory surprised everyone at the election."
not likely to be true or to occur or to have occurred
"legislation on the question is highly unlikely"
"an improbable event"
has little chance of being the case or coming about
"an unlikely story"
"an unlikely candidate for reelection"
"a butcher is unlikely to preach vegetarianism"
having a probability too low to inspire belief
"Winning the lottery without buying a ticket is highly unlikely given that no such event has ever been recorded in history."
Not likely; improbable; not to be reasonably expected.
"It is highly unlikely that we will finish the project before sunset given how much work remains."
In plain English: Unlikely means something is not expected to happen because it has very little chance of occurring.
"It is unlikely that we will finish this project by tomorrow given our current schedule."
Usage: Use unlikely as an adjective before nouns, such as in "an unlikely candidate," rather than using it alone where a noun is required. Avoid confusing this with the adverb unlikeliness, which is not standard English; instead use phrases like "it is unlikely."
In an improbable manner.
"The magician made the impossible coin vanish in an unlikely manner that left the audience stunned."
The word unlikely comes from Middle English and is formed by adding the prefix "un-" to mean "not probable." It entered modern usage as a straightforward negation of the concept of being likely.