Green’s Dictionary of Slang

1. (also whippy kick) a pocket.

1967		Kings Cross Whisper (Sydney) xliii 11/2: whippy: Pocket. Sometimes whip your kick, or willy, same as wallet.
1983		R. Aven-Bray Ridgey-Didge Oz Jack Lang 52: Whippy Kick Pocket where money is kept.
1983		J. Byrell (con. 1959) Up the Cross 162: ‘Some small change from his hip whippy’.

2. a hiding place, esp. for money.

1973

Kings Cross Whisper (Sydney) cliv 16/2: I’ve never yet met a Kiwi who didn’t cry poor mouth while he snipped you bone dry and all the time had a secret whippy tucked away somewhere you didn’t know about [AND].

3. a wallet.

1967		see sense 1.
1983		R. Aven-Bray Ridgey-Didge Oz Jack Lang 10: The vanilla fudge had hit him up for fifty Oxford scholars. It was a hefty blow on his whippy at that time.

4. a reserve of money, a profit.

1991

R.G. Barrett Between the Devlin 19: [T]here should be a bit of a whippy in hand. It had been almost three years since he’d checked on the old block of flats [...] The place could be worth anything by now.