peter out

From peter (“of a vein of ore: to be depleted of ore; to diminish to nothing”) + out. The etymology of peter is unknown; the following have been suggested:

• From peter (“to stop doing or saying something”).[1][2]
• Since the word was first used in mining contexts, either:[2]
  • from French péter (“to explode; to break wind, fart”); or
  • from (salt)peter, a variant of saltpetre (“potassium nitrate”), the key ingredient in gunpowder.[3]

• (Received Pronunciation) IPA^(key): /ˌpiːtɚ‿ˈaʊt/
• (General American) IPA^(key): /ˌpitɚ‿ˈaʊt/, [-ɾɚ-]

• Audio (AU)

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• Rhymes: -aʊt
• Hyphenation: pe‧ter out

peter out (third-person singular simple present peters out, present participle petering out, simple past and past participle petered out)

1. (intransitive, originally US) Synonym of peter (“originally (mining), of a vein of ore: to be depleted of ore; now (generally), to diminish to nothing; to dwindle, to trail off”)

   Synonym: spin down

   What started as a great effort ended up petering out to nothing.

   • 1883, Robert Louis Stevenson, “With the Children of Israel. I. To Introduce Mr. Kelmar.”, in The Silverado Squatters, London: Chatto and Windus, […], →OCLC, page 60:

     But the luck had failed, the mines petered out; and the army of miners had departed, and left this quarter of the world to the rattlesnakes and deer and grizzlies, and to the slower but steadier advance of husbandry.

   • 2020 November 18, Paul Bigland, “New Infrastructure and New Rolling Stock”, in Rail, Peterborough, Cambridgeshire: Bauer Media, →ISSN, →OCLC, page 49:

     Soon, the overhead wires will reach here. My only hope is that common sense prevails, and that the overhead line equipment continues its march north rather than petering out, leaving a monument to short-term thinking and a lack of vision.

• “peter out”, in Dictionary.com Unabridged, Dictionary.com, LLC, 1995–present, reproduced from Christine Ammer, The American Heritage Dictionary of Idioms, Boston, Mass.: Houghton Mifflin, 2003, →ISBN.
• Gary Martin (1997–), “Peter out”, in The Phrase Finder.