Lines found on mug picked up in city once (6)
I believe the answer is:
odessa
'city once' is the definition.
I can't judge whether this defines the answer.
'lines found on mug picked up' is the wordplay.
'lines' becomes 'ode' (lines of poetry).
'found on' means one lot of letters go next to another.
'mug' becomes 'ass' (I've seen this before).
'picked up' says the letters should be written backwards.
'ass' reversed gives 'ssa'.
'ode'+'ssa'='ODESSA'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for odessa that I've seen before include "Ukrainian Black Sea port" , "Ukrainian naval base" , "Battleship Potemkin mutiny port" , "Seaport" , "Port city on the Black Sea" .)