Miles away from dirt (5)
I believe the answer is:
slime
'dirt' is the definition.
(thesaurus)
'miles away' is the wordplay.
'away' is an anagram indicator.
'miles' anagrammed gives 'SLIME'.
'from' acts as a link.
(Other definitions for slime that I've seen before include "Gunge" , "Nasty slippery stuff" , "Gunk" , "could make things sticky" , "Gooey seeping stuff" .)