Turn Gibson back, the dolt (5)
I believe the answer is:
golem
'dolt' is the definition.
Both the answer and definition are singular nouns.
Perhaps they are linked in a way I don't understand?
'turn gibson back' is the wordplay.
'turn' becomes 'go' (a person's move in a board game).
'gibson back' becomes 'lem' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'go'+'lem'='GOLEM'
'the' acts as a link.
Can you help me to learn more?
(Other definitions for golem that I've seen before include "something robotic" , "supernaturally animated" , "Human image brought to life" , "(In Jewish legend) a clay figure brought to life" , "Animated figure" .)