Etymograph

English

femto-

Femto- comes from Danish femten ‘fifteen’, and goes back to Proto-Germanic *fimftehun.

  1. Proto-Germanicc. 500 BCE–200 CE*fimftehun‘fifteen’reconstructed
  2. Old Norsec. 800–1350fimmtán‘fifteen’
  3. Danishmodernfemten‘fifteen’
  4. Englishtodayfemto-

attested reconstructed ? uncertain or disputed

Lineage

  1. Proto-Germanicc. 500 BCE–200 CE*fimftehun‘fifteen’reconstructed
  2. Old Norsec. 800–1350fimmtán‘fifteen’
  3. Danishmodernfemten‘fifteen’
  4. Englishtodayfemto-

A compound of *fimf ‘five’ + *tehun ‘ten’

Proto-Indo-European *pénkʷe ‘five’

Proto-Germanic *fimf ‘five’

Proto-Indo-European *déḱm̥ ‘ten’

Proto-Germanic *tehun ‘ten’

Linked words

through Proto-Germanic *fimftehun ‘fifteen’

fifteen, 3 more

Today it means

prefix In the International System of Units and other metric systems of units, multiplying the unit to which it is attached by 10⁻¹⁵ (short scale quadrillionth or long scale billiardth).

Language periods are conventional ranges, not dates for this word.

Etymograph / Proto-Germanic *fimftehun / femto-

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