Where two gentlemen were putting up an old cleric (6)
I believe the answer is:
verona
'where two gentlemen were' is the definition.
The answer is a location as well as being a singular noun. This is suggested by the definition.
'up an old cleric' is the wordplay.
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'cleric' becomes 'Rev' (abbreviation for Reverend).
'an'+'o'+'rev'='anorev'
'anorev' back-to-front is 'VERONA'.
'putting' acts as a link.
Can you help me to learn more?
(Other definitions for verona that I've seen before include "Romeo's city" , "Rave on in Italian city of Romeo and Juliet" , "Juliet's hometown" , "Where 27 [MERCUTIO] was killed" , "Rave on in town of Romeo and Juliet" .)