TOS

/tiː əʊ ɛs/

//tiː əʊ ɛs// noun

By · According to Wiktionary data (CC BY-SA) ·

"tos" is a 3-letter English headword indexed on PlainSpell.

The verdict

“TOS” sits in 20 confusable pairs (corpus #19,720) as a noun. The look-alike neighbours are the real trap.

#19,720
frequency rank, English
3,151
“T” headwords
20
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Initialism of terms of service.

Corpus desk

Index EN-tos · TOS · English

TOS · rank #19,720 · 0 variants · 20 confusables

  • FREQ-MID #19,720
  • LEN-MID 3 letters
  • VOW-1 1 vowel
  • CONFUS-HIGH 20 pairs
  • VAR-0 0 variants
  • BOOK-MID 3,151
  • PHOTO-FINISH TLC

Nearest frequency peer: TLC (-2 rank slots)

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.

Frequency neighbourhood for “TOS”

Lower corpus rank = more everyday usage (inverted bar length for readability)

corpus weight

What this shows Bars show where “TOS” sits against the nearest ranked English headwords in the FrequencyWords band, not a reprint of letter-browse containment.

Source FrequencyWords open word-frequency list As of September 3, 2026

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

TOS vs TV
33% similar
TOS vs TX
33% similar
TOS vs Tu
33% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for TOS
PropertyValue
HeadwordTOS
LanguageEnglish
Part of speechNoun
IPA/tiː əʊ ɛs/
Letters3
Frequency rank#19,720
Misspellings tracked0
Confusable pairs20
SourceWiktionary (kaikki.org)

Where “TOS” sits in English frequency

This scale runs from the tiny cluster of words that carry ordinary speech (left) to the long tail of words almost nobody reaches for (right).TOS lands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

The axis is logarithmic, with each marked tick roughly ten times rarer than the last. Source: FrequencyWords open word-frequency list.

Easy to mix with look-alikes

The spelling risk for TOS is neighbouring look-alikes ("TV", "TX", …), not just typos; it is anoun pronounced /tiː əʊ ɛs/. Frequency #19,720 among 3,151 “T” headwords. 2 recorded senses keep meaning in play.

No misspelling variants are generated for TOS in our index, typically a sign the spelling maps closely to how the word sounds. It also participates in 20 confusable-pair relationships, "TV", "TX", "Tu", and more, since the words sound or look close enough that writers reach for the wrong one mid-sentence.

No borrowing history is documented for this entry, so its spelling is easiest explained by how it's pronounced rather than where it came from. The correct English form is TOS, spelled T-O-S.

Definition

  1. 1
    Initialism of terms of service.
  2. 2
    Initialism of thoracic outlet syndrome.

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

PlainSpell is rendered directly from structured Wiktionary extracts and open word-frequency lists, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of September 3, 2026. Primary sources: Wiktionary (via kaikki.org) and FrequencyWords.

Frequently Asked Questions

How do you spell "TOS"?
"TOS" is spelled T-O-S. The IPA pronunciation is /tiː əʊ ɛs/.
What does "TOS" mean?
As a noun, "TOS" means: Initialism of terms of service.
What words are commonly confused with "TOS"?
"TOS" is commonly confused with "TV", "TX", "Tu". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "TOS"?
The IPA (International Phonetic Alphabet) transcription for "TOS" is /tiː əʊ ɛs/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What language does "TOS" come from?
"TOS" is a English word. You can look up definitions, pronunciations, and spelling data for this and other words across English, Spanish, Portuguese, French, and German on PlainSpell.
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.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "TOS", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 3 letters (nearest by frequency rank).

TLC#19,718taj#19,712veg#19,731VHS#19,733

What to do next

You've looked up "TOS". Here's where to go from here.

  • "TOS" maps to 20 confusable pairs in this vintage; the highest-scored is "TV". View pair
  • Usage frequency rank #19,720 among English headwords in this corpus. Corpus statistics
  • Browse more English words in the "T" letter cohort. T–Z browse
  • PlainSpell rotates a curated Word of the Day from the English corpus, a passive way to discover vocabulary. Word of the Day

PlainSpell is a reference corpus, not spelling advice. Verify unusual forms in context.

Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

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

Source: FrequencyWords open word-frequency list