MEANING:

to have no money at all; completely broke; entirely without funds; penniless

EXAMPLE SENTENCES:

I can’t even pay the rent this month. I’m flat broke.

Sorry, I’m flat broke. Not a cent on me.

We were flat broke at the time.

I can’t help you – I’m flat broke

You may be flat broke, but you will find a way to pay your electricity bill or you will live in the dark.

I’m flat broke. [ = I have no money]

Within six months he was flat broke and on the verge of being disbarred.

I can’t afford to go on holiday this year – I’m (flat) broke.