Daughter comes in to be apologetic for something impolite (4)
I believe the answer is:
rude
'impolite' is the definition.
(similar in meaning)
'daughter comes in to be apologetic for something' is the wordplay.
I cannot really see how this works, but
'daughter' could be 'd' (genealogical abbreviation) and 'd' is found within the answer.
The remaining letters 'rue' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for rude that I've seen before include "Ill-mannered and coarse" , "Uncivil" , "Primitive; impolite" , "Coarse, unpolished" , "Insolent" .)