Pin dubious statement on bias (6)
I believe the answer is:
skewer
'pin' is the definition.
(skewering is a kind of pinning)
'dubious statement on bias' is the wordplay.
'dubious statement' becomes 'er' (I am not sure about this - if you are sure you should believe this answer much more).
'on' means one lot of letters go next to another.
'bias' becomes 'skew' (synonyms).
'er' after 'skew' is 'SKEWER'.
Can you help me to learn more?
(Other definitions for skewer that I've seen before include "Kebab-securer" , "The heart of kebab" , "Metal pin for cooking" , "Pin holding the roast together" , "Long pin for holding meat during roasting" .)