that is to say

adv

"that-is-to-say" is a 11-letter English headword indexed on PlainSpell.

The verdict

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

Unranked
below top-frequency English
14
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - In other words. Used to introduce a clarification, simplification, or explanation

Corpus desk

Index EN-that-is-to-say · that is to say · English

that is to say · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-MEGA 14 letters
  • VOW-5 5 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "T" 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 that is to say
PropertyValue
Headwordthat is to say
LanguageEnglish
Part of speechAdverb
Letters14
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “that is to say” in English

that is to saysits beyond the 100,000 most-frequent English words, in the long tail of technical, archaic, or otherwise rare vocabulary where spelling doubt tends to strike hardest.

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

Rare enough to double-check

that is to say is uncommon English outside the top frequency list, classed as anadverb. Rarity is why readers land here mid-draft. Gloss: "In other words. Used to introduce a clarification, simplification, or explanation".

Our edit-distance generator produced no likely misspellings for that is to say, since its letter sequence doesn't invite the usual edit-distance slips. We don't track a confusable pairing for this entry, which usually means its spelling is distinct enough that readers don't reach for a similar-looking word instead.

Etymologically, the entry records: Calque of French c'est-à-dire. The correct English form is that is to say, spelled T-H-A-T- -I-S- -T-O- -S-A-Y.

Definition

  1. 1
    In other words. Used to introduce a clarification, simplification, or explanation

Recorded use

Wiktionary example

These source excerpts show how that is to say appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. One of the best things about works of music is that they are repeatable, that is to say that one can listen to the same work over and over without becoming tired of it.

Etymology

Calque of French c'est-à-dire.

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 "that is to say"?
"that is to say" is spelled T-H-A-T- -I-S- -T-O- -S-A-Y.
What does "that is to say" mean?
As an adverb, "that is to say" means: In other words. Used to introduce a clarification, simplification, or explanation
What is the origin of the word "that is to say"?
Calque of French c'est-à-dire. 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