Not repeated, not happening again
1. Former, sometime
2. Occurring only once; one-shot
ETYM French unique; cf. Italian unico; from Latin unicus, from unus one. Related to One.
1. Highly unusual or rare but not the single instance.
2. (Followed by 'to') Applying exclusively to a given category or condition or locality.
3. The single one of its kind
4. Highly unusual or rare but not the single instance
Having no parallel, or equal; unequaled; unmatched.
So as to be unique; SYN. unambiguously.