Crazy guy gives joke to chamber (8)
I believe the answer is:
crackpot
'crazy' is the definition.
(I've seen this before)
'guy gives joke to chamber' is the wordplay.
I cannot quite see how this works, but
'joke' could be 'crack' (a crack is a joke or quip) and 'crack' is located in the answer.
'chamber' could be 'po' (I've seen this in other clues) and 'po' is present in the answer.
A single letter 't' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for crackpot that I've seen before include "Eccentric (colloq.)" , "Nut" , "Crank" , "Informal eccentric like damaged utensil" , "Damage utensil for informally eccentric person" .)