Breeder, Frenchman perhaps, taken aback about sex (10)

'breeder frenchman' is the definition.
The definition suggests a singular noun which matches the answer.

'taken aback about sex' is the wordplay.
I cannot quite see how this works, but
'about' could be 're' ('re' means regarding or about) and 're' is found within the answer.
'sex' could be 'gender' (synonyms) and 'gender' is found within the answer.
The remaining letters 'en' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...

'perhaps' is the link.

Can you help me to learn more?