W: (adj) opaque [Related to: opacity] (not transmitting or reflecting light or radiant energy; impenetrable to sight) "opaque windows of the jail"; "opaque to X-rays"
S: (n) opacity, opaqueness (incomprehensibility resulting from obscurity of meaning)
S: (n) opacity, opaqueness (the quality of being opaque to a degree; the degree to which something reduces the passage of light)