Boob shown as Terry and Norm disrobe (5)
I believe the answer is:
error
'boob' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for error that I've seen before include "Fallacy, mistake" , "Mistake or fault" , "Faulty judgment" , "wrong" , "Mistake, lapse" .)