Haughty, awful pain, old Joanna (5,5)
I believe the answer is:
grand piano
'joanna' is the definition.
Both the definition and answer are singular nouns.
Perhaps you can see an association between them that I don't see?
'haughty awful pain old' is the wordplay.
'haughty' becomes 'grand' (I can't explain this - if you can you should give a lot more credence to this answer).
'awful' indicates anagramming the letters.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'pain' is an anagram of 'pian'.
'grand'+'pian'+'o'='GRAND PIANO'
Can you help me to learn more?
(Other definitions for grand piano that I've seen before include "Large instrument with horizontal strings" , "Large stringed instrument" , "Keyboard instrument" , "maker of notes?" , "One's three-legged" .)