Sludge from miles away (5)
I believe the answer is:
slime
'sludge' is the definition.
(I know that sludge can be written as slime)
'miles away' is the wordplay.
'away' indicates an anagram (letters move away from their original places).
'miles' with letters rearranged gives 'SLIME'.
'from' is the link.
(Other definitions for slime that I've seen before include "Goo" , "Gooey seeping stuff" , "Sludge, gloop" , "Nasty slippery stuff" , "Moist slippery stuff" .)