Live at the East End as a gamble (3)
I believe the answer is:
bet
'a gamble' is the definition.
(bet is a kind of gamble)
'live at the east end' is the wordplay.
'live' becomes 'be' (synonyms).
'the east end' says to take the final letters (the letter on the right or east end of the word).
The last letter of 'at' is 't'.
'be'+'t'='BET'
'as' acts as a link.
(Other definitions for bet that I've seen before include "Money risked on a gamble" , "Wager, or the sum waged" , "Wager, gamble" , "'Stake, wager (3)'" , "22 across will accept one" .)