Slumber can interpret and disentangle (10)
I believe the answer is:
unscramble
'disentangle' is the definition.
(thesaurus)
'slumber can interpret' is the wordplay.
'interpret' indicates anagramming the letters.
'slumber'+'can'='slumbercan'
'slumbercan' is an anagram of 'UNSCRAMBLE'.
'and' acts as a link.
(Other definitions for unscramble that I've seen before include "Restore to readability" , "Restore to a readable state" .)