From Longman Dictionary of Contemporary Englishpeterpe‧ter /ˈpiːtə $ -ər/ verb → peter out→ See Verb table
Examples from the Corpus
peter• The houses began to peter out, and eventually stopped.• Traffic began to peter out and they found themselves in the middle of extensive minefields.• That hot-spot eruption lasted some 2 million years before petering out to a more modest flow.• Within a very short distance of the airport, roads peter out to cattle tracks.• Some believe the protests will eventually peter out.• The effects of the devaluation are now petering out.Origin peter (1800-1900) Origin unknown 