Not transparent; opaque or unable to allow light to pass through.
From Greek 'a-' (not) + 'diaphanous' (transparent), which comes from 'dia-' (through) + 'phainein' (to show). The prefix was added to create the opposite meaning.
This word is the opposite of 'diaphanous'—while diaphanous describes the delicate, see-through quality of things like gossamer fabric or butterfly wings, adiaphanous means the complete opposite: solid, opaque, and light-blocking.
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