thereunder

adv

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

"thereunder" is a 10-letter English headword indexed on PlainSpell.

The verdict

“thereunder” is uncommon English (frequency #83,812 among 27,828 “T” headwords), classed as an adverb. The kind of spelling people second-guess.

#83,812
frequency rank, English
27,828
“T” headwords

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Under that; under it.

Key facts for thereunder
PropertyValue
Headwordthereunder
LanguageEnglish
Part of speechAdverb
Letters10
Frequency rank#83,812
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Where “thereunder” sits in English frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right). thereunder lands here:

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

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

Rare enough to double-check

thereunder is uncommon English at frequency #83,812 among 27,828 “T” headwords, classed as anadverb. Rarity is why readers land here mid-draft. Gloss: "Under that; under it.".

We couldn't generate a plausible misspelling set for thereunder, since its letter sequence doesn't invite the usual edit-distance slips. No confusable counterpart is on file for this word, which typically means the spelling is too distinctive to be mistaken for another word.

Etymologically, the entry records: From Middle English therunder, þer-under, þar under, from Old English þǣrunder, equivalent to there + under. Cognate with Dutch daaronder (“thereunder”), German darunter (“thereunder”), Swedish därunder (“thereunder”). The correct English form is thereunder, spelled T-H-E-R-E-U-N-D-E-R.

Definition

  1. 1
    Under that; under it.

Etymology

From Middle English therunder, þer-under, þar under, from Old English þǣrunder, equivalent to there + under. Cognate with Dutch daaronder (“thereunder”), German darunter (“thereunder”), Swedish därunder (“thereunder”).

This word in other languages

darunter(Deutsch)

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.

Frequently Asked Questions

How do you spell "thereunder"?
"thereunder" is spelled T-H-E-R-E-U-N-D-E-R.
What does "thereunder" mean?
As an adverb, "thereunder" means: Under that; under it.
What is the origin of the word "thereunder"?
From Middle English therunder, þer-under, þar under, from Old English þǣrunder, equivalent to there + under. Cognate with Dutch daaronder (“thereunder”), German darunter (“thereunder”), Swedish därunder (“thereunder”). 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.

Using “thereunder”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is T-H-E-R-E-U-N-D-E-R - every other letter order is a misspelling in standard orthography.
  • Browse more English words and confusable pairs in the same reference. English words

Other uncommon English words near this rank

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 FrequencyWords open word-frequency list