Speakur

Word Pronunciation & Dictionary

femto-

Word Rarity Very rare

Frequency: Zipf frequency 1.69 in modern English

Syllables
fem-to-
IPA
10
Scrabble Score
5
Letters
3
Syllables
5
Unique Chars

Meaning

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).

Etymology

Etymology tree Proto-Indo-European *pénkʷe Proto-Germanic *fimf Proto-Indo-European *déḱm̥ Proto-Germanic *tehun Proto-Germanic *fimftehun Old Norse fimmtánder. Danish femtender. English femto- From Danish femten (“fifteen”), with reference to the (negative) exponent in the relevant power of ten; the same principle also explains atto-.

Origin

Word Breakdown

Frequently Paired Words

mul:f-

Antonyms

peta-

Questions

What does femto- mean?
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).
Where does femto- come from?
It is traced to Danish.

How to pronounce femto-

  1. Open the pronunciation page — Open the Speakur entry for “femto-”.
  2. Read the phonetic spelling — Read the IPA spelling () so you know which sounds to aim for.
  3. Play the audio — Click Play to hear reference audio for “femto-”.
  4. Repeat and practice — Say “femto-” aloud, matching stress and vowels until it feels natural.