Cause of a snore? (6)
I believe the answer is:
reason
'cause' is the definition.
(I've seen this before)
'of a snore?' is the wordplay.
'of' is an anagram indicator (the answer comes from or 'of' the letters).
'a'+'snore'='asnore'
'asnore' is an anagram of 'REASON'.
(Other definitions for reason that I've seen before include "Logic of senora" , "Motivation or justification" , "issue" , "Defence" , "Explanation or justification" .)