Posh officer married teacher in need of a groom (8)
I believe the answer is:
coiffure
'a groom' is the definition.
(I know that coiffure is a type of groom)
'posh officer married teacher' is the wordplay.
I cannot quite see how this works, but
'posh' could be 'u' (abbreviation for upper-class - opposite to non-U) and 'u' is found in the answer.
an anagram of 'officer' is 'coiffre' which is present in the remaining letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'in need of' acts as a link.
Can you help me to learn more?
(Other definitions for coiffure that I've seen before include "set" , "Hairdo" , "French hairstyle" .)