Rare; not common or usual
The definition of unique is one of a kind.
The definition of unprecedented is something that has not happened before.
Having been made or come into being only a short time ago; recent:
Not to be believed; incredible:
Well above average; extraordinary:
Not usual, common, or ordinary.
The definition of novel is something new or different.
An unknown mathematical quantity; also, a symbol for this
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.
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, unprecedented, new, unbelievable, exceptional, unusual, novel, unknown, normal and usual.