Desk forced open? That is acceptable (4-4)
I believe the answer is:
prie-dieu
'desk' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'forced open? that is acceptable' is the wordplay.
'forced open?' becomes 'pried' (I've seen this in another clue).
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'acceptable' becomes 'u' (as in U and non-U speech).
'pried'+'ie'+'u'='PRIE-DIEU'
Can you help me to learn more?
(Other definitions for prie-dieu that I've seen before include "I'd 1 rupee (anag) - prayer desk" , "It's knelt on for prayer" , "On which to kneel and pray" , "Desk at which one kneels to pray" , "Item of furniture used for praying" .)