Tinker means to butt in (6)
I believe the answer is:
meddle
This clue is a double definition.
'tinker' is the first definition.
(I've seen this before)
'to butt in' is the second definition.
(thesaurus)
'means' acts as a link.
(Other definitions for meddle that I've seen before include "Mess with" , "Pink Floyd album" , "Interfere unnecessarily" , "Stick one's oar in" , "Interfere in people's affairs" .)