19 across
Risk
money
accepting
a
flutter
(4)
Risk money accepting a flutter (4)
hints
0
checks
0
hints
The definition is at the end of the clue.
How the clue works
Right, so flutter's your definition here, as in a heartbeat. Take BET — that's "risk money", a wager — and pop A inside it, and you get BE-A-T, which spells out BEAT.