Place for better walking amid banks of greenish Yorkshire river (8,5)

'place for better' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.

'walking amid banks of greenish yorkshire river' is the wordplay.
'walking' becomes 'ambling' (ambling is a kind of walking).
'amid' indicates putting letters inside.
'banks of' suggests removing the centre (the banks are the sides of the word).
'yorkshire river' becomes 'ouse' (the Ouse is a river in Yorkshire).
'greenish' with its middle removed is 'gh'.
'ambling' put into 'gh' is 'gamblingh'.
'gamblingh'+'ouse'='GAMBLING-HOUSE'

Can you help me to learn more?