A potato, for example, for an awful brute (5)
I believe the answer is:
tuber
'a potato for example' is the definition.
(potato is an example of a tuber)
'an awful brute' is the wordplay.
'an awful' indicates an anagram.
'brute' anagrammed gives 'TUBER'.
'for' is the link.
(Other definitions for tuber that I've seen before include "Rhizome, as of potato" , "Underground stem, root" , "Root of potato etc" , "A brute of a spud" , "Fleshy underground root" .)