femtojoule

F4E1M3T1O1J8O1U1L1E1

noun

An SI unit of energy, work, and heat equal to 10⁻¹⁵ joules. Symbol: fJ

Similar
fJ
OriginEnglish joule ← Danish femten ← Old Norse fimmtán →
Scrabble 22
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Meanings

nounfemtojoule (plural femtojoules)

plural femtojoules

  1. metrologyAn SI unit of energy, work, and heat equal to 10⁻¹⁵ joules. Symbol: fJ

    Synonyms: fJ

Synonyms & antonyms

nounAn SI unit of energy, work, and heat equal to 10⁻¹⁵ joules. Symbol: fJ

Similar
fJ

Origin

  1. Proto-Indo-European*pénkʷe
  2. Proto-Germanic*fimf
  3. Proto-Indo-European*déḱm̥
  4. Proto-Germanic*tehun
  5. Proto-Germanic*fimftehun
  6. Old Norsefimmtán
  7. Danishfemten
  8. Englishfemto-
  9. Englishjoule
  10. Englishfemtojoule

From femto- + joule.

Full word history & related roots →
Cite this entry
APA

femtojoule. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/femtojoule

MLA

“femtojoule.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/femtojoule. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “femtojoule,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/femtojoule.

Source: femtojoule on Wiktionary, CC BY-SA 4.0.