Boy comes down from Oxford as one? (6)
I believe the answer is:
unison
'as one?' is the definition.
(I've seen this before)
'boy comes down from oxford' is the wordplay.
I cannot quite see how this works, but
'boy' could be 'son' (synonyms) and 'son' is present in the answer.
The remaining letters 'uni' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for unison that I've seen before include "Togetherness - TUC member" , "using same pitch" , "All singing the same notes" , "Accord" , "Unscrupulous dealer" .)