Material relating to the sides of the skull (8)

I believe the answer is:

temporal

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'material' is the definition.
(thesaurus)

I can't explain the rest of the clue.

(Other definitions for temporal that I've seen before include "Nothing spiritual" , "about the side of the head" , "on the Head's side?" , "Of wordly affairs, not spiritual" , "Relating to time" .)

I've seen this clue in The Hindu.

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