“Very unique” doesn’t work. But if there were two of something, wouldn’t one of them be “almost unique?”
:)
How about the word ‘rare’? For example, “It is an almost unique event for a woman to have quintuplets.” versus “It is a rare event for a woman to have quintuplets.” (Stats that I’ve seem show 1 in 55,000,000 births are quints.) If you had an identical twin, would you be ‘unique’ or ‘almost unique’?
Of course, that brings up another pet peeve, the phrase ‘unique individual’, which is often heard. Even worse: ‘a very unique individual’! By definition, an ‘individual’ something IS ‘unique’ or one of a kind, so ‘very’ adds additional redundancy to an already redundant sentence.