WD-40

US/ˌdʌb(əl)ju ˌdi ˈfɔɹti/

proper noun

A penetrating oil used as a universal solvent, a lubricant and to protect electric circuits from moisture.

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Meanings

proper noun
  1. A penetrating oil used as a universal solvent, a lubricant and to protect electric circuits from moisture.
  2. broadlyidiomaticAnything or anyone that has many different uses.

Origin

Trademark; an abbreviation of "Water Displacement, 40th formula" or "40th attempt" used by Norm Larson of the Rocket Chemical Company of California, the oil's developer.

Full word history & related roots →
Cite this entry
APA

WD-40. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/WD-40

MLA

“WD-40.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/WD-40. Accessed November 3, 2026.

Chicago

WatkinsX Dictionary, s.v. “WD-40,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/WD-40.

Source: WD-40 on Wiktionary, CC BY-SA 4.0.