Euphemism for cracking a nasty fart.
Although it can used in reference to all kinds of farts, from the subtle to the divine, it is especially fitting for the absurdly obscene ones in particular.
Derived from the signature "ribbit" noise that frogs make, used to mimic the gas clawing its way out of your butt.
1. What the hell was that noise Jim? Sounded like someone just died.

Stepped on a frog. Big, nasty wart-covered frog.

2. Who just shit their pants?

Stepped on a frog. I can't help it mom, they are all over the damn floor. They are literally jumping under my every step. Be a good woman and clean this place up.
by barbados118 June 4, 2011
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(vb) to break or pass wind; to expel air through one's anus; to chuff; to whistle through one's Y-fronts; to let Polly out of prison; to drop one; to let go.....
Aaaaaaaagh! That MINGS! Our Mark's just stepped on a frog- again!!...

Chalky leaned casually forward from the sofa, picked up the remote; and stepped blithely on a frog. He chuckled and intoned 'Beat THAT!!'
by Blueboy May 7, 2004
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