atto-

[ˈat̪o]

/[ˈat̪o]/ prefix

The verdict

“atto-” is uncommon Spanish (outside the top frequency list), classed as a prefix. The kind of spelling people second-guess.

Unranked
below top-frequency Spanish
5
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Prefijo del Sistema Internacional utilizado para denotar la trillonésima parte de la unidad o la multiplicación por un factor de 10⁻¹⁸. Su símbolo es a.

Corpus desk

Index ES-atto · atto- · Spanish

atto- · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-MID 5 letters
  • VOW-2 2 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "A" thin
  • PHOTO-UNK Peer pending

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Key facts for atto-
PropertyValue
Headwordatto-
LanguageSpanish
Part of speechPrefix
IPA[ˈat̪o]
Letters5
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Cola larga: rango de “atto-” en español

atto-no entra en el top 100.000 del español: zona de términos técnicos, arcaicos o escasos, el terreno típico de la doble comprobación.

Beyond rank #100,000. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

atto- is uncommon Spanish outside the top frequency list, classed as aprefix, transcribed [ˈat̪o]. Rarity is why readers land here mid-draft. Gloss: "Prefijo del Sistema Internacional utilizado para denotar la trillonésima parte de la unidad o la multiplicación por un factor de 10⁻¹⁸. Su símbolo es a.".

The misspelling generator found no plausible variants for atto-, a sign its spelling follows regular Spanish conventions. This headword has no recorded confusable partner, since its spelling is unusual enough that it doesn't cluster with a lookalike.

This headword's origin isn't recorded in our source data, so its spelling is easiest to reason about phoneme by phoneme, absent a documented history. The correct Spanish form is atto-, spelled A-T-T-O--.

Definition

  1. 1
    Prefijo del Sistema Internacional utilizado para denotar la trillonésima parte de la unidad o la multiplicación por un factor de 10⁻¹⁸. Su símbolo es a.

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "atto-"?
"atto-" is spelled A-T-T-O--. The IPA pronunciation is [ˈat̪o].
What does "atto-" mean?
As a prefix, "atto-" means: Prefijo del Sistema Internacional utilizado para denotar la trillonésima parte de la unidad o la multiplicación por un factor de 10⁻¹⁸. Su símbolo es a.
How do you pronounce "atto-"?
The IPA (International Phonetic Alphabet) transcription for "atto-" is [ˈat̪o]. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What language does "atto-" come from?
"atto-" is a Spanish word. PlainSpell covers definitions, pronunciations, and spelling data across English, Spanish, Portuguese, French, and German.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list