atto-

From Danish atten (“eighteen”), extending the idea to how femto- is derived from Danish femten (“fifteen”) and the fermi unit.

atto-

1. In the International System of Units and other metric systems of units, multiplying the unit to which it is attached by 10⁻¹⁸ (short scale quintillionth or long scale trillionth). Symbol: a

• exa-

• to a T, toat, tota

Borrowed from Danish atten (“eighteen”).

atto-

1. atto-

• “atto-” in Diccionari de la llengua catalana, segona edició, Institut d’Estudis Catalans.
• “atto-”, in Gran Diccionari de la Llengua Catalana, Grup Enciclopèdia Catalana, 2025
• “atto-” in Diccionari normatiu valencià, Acadèmia Valenciana de la Llengua.

From atten (“eighteen”).

atto-

1. atto-

Dutch Wikipedia has an article on:

Atto

Wikipedia ^nl

From Danish atten (“eighteen”).

• IPA^(key): /ˈɑ.toː/

• Audio:

  (file)

atto-

1. atto-

Internationalism (see English atto-).

• IPA^(key): /ˈɑtːo-/,

atto-

1. atto-

• “atto-”, in Kielitoimiston sanakirja [Dictionary of Contemporary Finnish]‎ (in Finnish) (online dictionary, continuously updated), Kotimaisten kielten keskuksen verkkojulkaisuja 35, Helsinki: Kotimaisten kielten tutkimuskeskus (Institute for the Languages of Finland), 2004–, retrieved 2023-07-02

• otat, taot, tota

• Audio:

  (file)

atto-

1. atto-

From Danish atten.

• IPA^(key): /at.tɔ/

• Audio:

  (file)

• Rhymes: -attɔ
• Syllabification:

atto-

1. atto-

   ‎atto- + ‎sekunda → ‎attosekunda

• atto- in Polish dictionaries at PWN

Borrowed from Danish atten (“eighteen”).

• IPA^(key): /ˈadto/
• Rhymes: -adto

atto-

1. atto-

• “atto-”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8, Royal Spanish Academy [Spanish: Real Academia Española], 2024 December 10