Making one feel guilty, is irritating (4,5)
I believe the answer is:
hair shirt
'making one' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'feel guilty is irritating' is the wordplay.
I cannot really understand how this works, but
'feel' could be 'air' (I've seen this before) and 'air' is found within the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for hair shirt that I've seen before include "Hirsute penitential garment for men" , "uncomfortable clothing" , "Traditional wear of ascetic" , "Penitential hirsute garment for upper part of man's body" , "Coarse hirsute garment worn over skin as a penance" .)