Unique is an absolute term except in contract-specific-performance law.

Evidence

Strictly speaking, unique is an absolute term meaning “one of a kind.” In common usage it can’t take an intensive modifier <very unique [read unique]>. Using unique loosely to mean unusual is not normally acceptable in formal writing. But in contract law, the term is used in a less-than-absolute sense when addressing the adequacy of money damages in a prayer for specific performance . — Bryan A. Garner, Jeff Newman, Tiger Jackson, The Redbook, 1199

Categorization

• DEFINE: Explains both the strict absolute usage and its recognized exception in contract law.