ad infinitum

/æd ˌɪn.fəˈnaɪ.təm/

//æd ˌɪn.fəˈnaɪ.təm// adv

"ad-infinitum" is a 11-letter English headword indexed on PlainSpell.

The verdict

“ad infinitum” is uncommon English (outside the top frequency list), classed as an adverb. The kind of spelling people second-guess.

Unranked
below top-frequency English
12
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Endlessly; for ever; never-endingly.

Corpus desk

Index EN-ad-infinitum · ad infinitum · English

ad infinitum · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-MEGA 12 letters
  • VOW-5 5 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "A" thin
  • PHOTO-UNK Peer pending

Read with this headword: Spelling guide for this pattern

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 ad infinitum
PropertyValue
Headwordad infinitum
LanguageEnglish
Part of speechAdverb
IPA/æd ˌɪn.fəˈnaɪ.təm/
Letters12
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “ad infinitum” in English

ad infinitumfalls outside the top-100,000 ranked English words, the long-tail zone of technical, archaic, or low-frequency vocabulary, exactly where readers second-guess spellings most.

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

Rare enough to double-check

ad infinitum is uncommon English outside the top frequency list, classed as anadverb, transcribed /æd ˌɪn.fəˈnaɪ.təm/. Rarity is why readers land here mid-draft. Gloss: "Endlessly; for ever; never-endingly.".

ad infinitum doesn't appear in our generated misspelling index, which points to an orthography that plays by predictable English rules. This entry stands alone in our confusable dataset, a sign it's visually distinctive enough not to be mixed up with another word.

Etymologically, the entry records: Unadapted borrowing from Latin ad īnfīnītum (“to infinity”). The correct English form is ad infinitum, spelled A-D- -I-N-F-I-N-I-T-U-M.

Definition

  1. 1
    Endlessly; for ever; never-endingly.

Recorded use

Wiktionary example

These source excerpts show how ad infinitum appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. The idea of eternal return is a mysterious one, and Nietzsche has often perplexed other philosophers with it: to think that everything recurs as we once experienced it, and that the recurrence itself recurs ad infinitum!

Etymology

Unadapted borrowing from Latin ad īnfīnītum (“to infinity”).

This word in other languages

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 "ad infinitum"?
"ad infinitum" is spelled A-D- -I-N-F-I-N-I-T-U-M. The IPA pronunciation is /æd ˌɪn.fəˈnaɪ.təm/.
What does "ad infinitum" mean?
As an adverb, "ad infinitum" means: Endlessly; for ever; never-endingly.
How do you pronounce "ad infinitum"?
The IPA (International Phonetic Alphabet) transcription for "ad infinitum" is /æd ˌɪn.fəˈnaɪ.təm/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "ad infinitum"?
Unadapted borrowing from Latin ad īnfīnītum (“to infinity”). See the full etymology section above for more details.
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