Cringing when old boys, Etonians primarily, question debts (10)
I believe the answer is:
obsequious
'cringing' is the definition.
(thesaurus)
'old boys etonians primarily question debts' is the wordplay.
'old boys' becomes 'OBs' (OB is short for old boy).
'primarily' indicates taking the first letters.
'question' becomes 'qu'.
'debts' becomes 'IOUs' (promises to pay debts).
The initial letter of 'etonians' is 'e'.
'obs'+'e'+'qu'+'ious'='OBSEQUIOUS'
'when' acts as a link.
(Other definitions for obsequious that I've seen before include "cringing?" , "Sycophantic" , "Fawning" , "Servile" .)