About to go astray ending with nothing here, I bet (6)

I believe the answer is:
casino
'here i bet' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'about to go astray ending with nothing' is the wordplay.
'about' becomes 'ca' (short for circa).
'to go astray' becomes 'sin' (I've seen this in another clue).
'ending with' is a charade indicator (letters next to each other).
'nothing' becomes 'O' (looks like zero - 0).
'ca'+'sin'+'o'='CASINO'
Can you help me to learn more?
(Other definitions for casino that I've seen before include "--- Royale (Fleming)" , "Gaming house" , "Where one may gamble" , "Gaming club" , "Gambling venue" .)
