Scotsman needing gold in gambling mecca (5)
I believe the answer is:
macau
'gambling mecca' is the definition.
(Macau is famous for gambling)
'scotsman needing gold' is the wordplay.
'scotsman' becomes 'mac'.
'needing' means one lot of letters go next to another.
'gold' becomes 'Au' (Au is the chemical symbol for gold).
'mac'+'au'='MACAU'
'in' acts as a link.
(Other definitions for macau that I've seen before include "somewhere in China" , "SW of 24 [SHANGHAI]" , "Part of China" , "Small peninsula in China, a Portuguese territory until 1999" , "region of China" .)