opaque opaque /oʊˈpeɪk/

adjective

1. () Not transmitting or reflecting light or radiant energy; impenetrable to sight  ( opaque )
   not transmitting or reflecting light or radiant energy; impenetrable to sight
    Opaque windows of the jail
   opaque windows of the jail
    Opaque to X-rays
   opaque to X-rays
   
2. Hard or impossible to understand  ( opaque , unintelligible )
   hard or impossible to understand