Male is left in clobber, like a stuffed shirt? (4)

I believe the answer is:

smug

I'm a little stuck... Click here to teach me more about this clue!

'like a stuffed shirt?' is the definition.
(I've seen this before)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for smug that I've seen before include "Self-satisfied, complacent" , "Conceited and self-satisfied" , "Arrogantly complacent" , "looking pleased with itself" , "Arrogantly self-satisfied" .)

I've seen this clue in the Sydney Morning Herald.

Want a hint initially instead of a full solution? Install my app