Wrath associated with posh doctor giving offence (7)
I believe the answer is:
umbrage
'offence' is the definition.
(I know that offence can be written as umbrage)
'wrath associated with posh doctor' is the wordplay.
'wrath' becomes 'rage' (I've seen this before).
'associated with' says to put letters next to each other.
'posh' becomes 'u' (abbreviation for upper-class - opposite to non-U).
'doctor' becomes 'MB' (Bachelor of Medicine, Medicinae Baccalaureus).
'u'+'mb'='umb'
'rage' put after 'umb' is 'UMBRAGE'.
'giving' acts as a link.
(Other definitions for umbrage that I've seen before include "Take this to show offence" , "Feeling of offence" , "In high dudgeon" , "Offence, annoyance" , "The sulks" .)