Polytypes

noun

1. Any of the types involved in polytypism.

   "Orthochrysotile is a polytype of chrysotile."

2. A cast, or facsimile copy, of an engraved block, matter in type, etc.
3. In the Hindley–Milner type system, a data type containing variables bound by one or more ∀ (for-all) quantifiers.