Erratic DIY nut is far from neat! (6)
I believe the answer is:
untidy
'far from neat' is the definition.
(I've seen this before)
'erratic diy nut' is the wordplay.
'erratic' indicates an anagram.
'diy'+'nut'='diynut'
'diynut' is an anagram of 'UNTIDY'.
'is' is the link.
(Other definitions for untidy that I've seen before include "missing order" , "Messy, not neat" , "Disorderly, slipshod" , "Disorderly and slovenly" , "Scruffy" .)