UNIQUE is validvalid

very unusual [adj UNIQUER, UNIQUEST] : UNIQUELY [adv], UNIQUENESS [n] / something that is unique [n UNIQUES]

30,336 of 196,601 in NWL2023·also valid in CSW24

having no other of its kind [adj UNIQUER, UNIQUEST, UNIQUELY] / anything that is unique [n -S]