Opaquer

adjective

1. Neither reflecting nor emitting light.
2. Allowing little light to pass through, not translucent or transparent.
3. Unclear, unintelligible, hard to get or explain the meaning of
4. Obtuse, stupid.
5. Describes a type for which higher-level callers have no knowledge of data values or their representations; all operations are carried out by the type's defined abstract operators.