Where Does the Expression Petering out Come from?

1846 US miners' slang, from 1812 peter (“to become exhausted”). Various speculative etymologies have been suggested, either from St. Peter (from the sense of “rock”), French péter (“to fart”), or saltpeter (ingredient in gunpowder, hence used in mining).

What is the meaning of petering out?

: to gradually become smaller, weaker, or less before stopping or ending Their romantic relationship petered out after the summer. Interest in the sport is beginning to peter out.

What does the word petering mean?

To diminish slowly and come to an end. Often used with out: Their enthusiasm soon petered out.