Saloon at the Nag's Head possibly used for a dance (4)
I believe the answer is:
barn
'for a dance' is the definition.
(thesaurus)
'saloon at the nag's head' is the wordplay.
'saloon' becomes 'bar' (synonyms).
'at' is a charade indicator (letters next to each other).
'head' suggests taking the first letters.
The initial letter of 'nags' is 'n'.
'bar'+'n'='BARN'
'possibly used' is the link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for barn that I've seen before include "stable" , "Outlying farm building" , "Large farm building" , "Farm storehouse" , "Housing for farm animals" .)