Mark mused wretchedly embracing godhead (6)
I believe the answer is:
smudge
'mark' is the definition.
(I've seen this before)
'mused wretchedly embracing godhead' is the wordplay.
'wretchedly' indicates an anagram (a wretched spelling).
'embracing' is an insertion indicator.
'godhead' becomes 'g' (head letter of 'god').
'mused' is an anagram of 'smude'.
'smude' enclosing 'g' is 'SMUDGE'.
(Other definitions for smudge that I've seen before include "Blur, smear" , "'Smear, daub (6)'" , "Choking smoke" , "A dirty or blurred mark" , "blurred impression" .)