Johnson now possibly showing resistance after blunder (6)
I believe the answer is:
gaffer
'johnson now' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'showing resistance after blunder' is the wordplay.
I cannot quite see how this works, but
'resistance' could be 'r' (electronics abbreviation) and 'r' is located in the answer.
'blunder' could be 'gaffe' (gaffe is a kind of blunder) and 'gaffe' is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'possibly' acts as a link.
Can you help me to learn more?
(Other definitions for gaffer that I've seen before include "Old man" , "Senior electrician on a film/TV set" , "Superior" , "one prone to blunder socially?" , "Foreperson of a work squad" .)