Rare; not common or usual
The definition of unique is one of a kind.
Unknown means something that people are not aware of or familiar with.
The definition of unprecedented is something that has not happened before.
Not usual, common, or ordinary.
Having been made or come into being only a short time ago; recent:
The definition of novel is something new or different.
Regularly or customarily used:
Difficult to understand.
Going far beyond the ordinary degree, measure, limit, etc.; very unusual; exceptional; remarkable
Having the nature of, involving, or doing great injury or wrong
Infrequently occurring; uncommon:
The definition of strange is an unfamiliar or unusual person, place or thing.
Not to be believed; incredible:
Well above average; extraordinary:
That cannot be described
Not known or not widely known by name
Find another word for unheard-of. In this page you can discover 26 synonyms, antonyms, idiomatic expressions, and related words for unheard-of, like: uncommon, unique, unknown, unprecedented, unusual, new, novel, normal, usual, familiar and obscure.