Enum has one meaning in C family languages. Other languages may have different meanings. For example, in Haskell something is an enum if there is an invertible

Enum has one meaning in C family languages. Other languages may have different meanings. For example, in Haskell something is an enum if there is an invertible mapping between that type and (a contiguous subset of) the machine integers (with complications). In other languages the concept might correspond to (finite) recursively enumerable sets (ie you can list all their elements).