thallus

/ˈθæl.əs/

//ˈθæl.əs// noun

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

"thallus" is a 7-letter English headword indexed on PlainSpell.

The verdict

“thallus” is uncommon English (frequency #89,988 among 27,828 “T” headwords), classed as a noun. The kind of spelling people second-guess.

#89,988
frequency rank, English
27,828
“T” headwords

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - An undifferentiated plant body, such as in algae.

Key facts for thallus
PropertyValue
Headwordthallus
LanguageEnglish
Part of speechNoun
IPA/ˈθæl.əs/
Letters7
Frequency rank#89,988
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Where “thallus” 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). thallus 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

thallus is uncommon English at frequency #89,988 among 27,828 “T” headwords, classed as anoun, transcribed /ˈθæl.əs/. Rarity is why readers land here mid-draft. 2 senses are on record.

Zero misspellings are on record for thallus in our index, since its letter pattern doesn't lend itself to common typo substitutions. No close-neighbour confusable shows up for this headword in our dataset, since no other headword is close enough in sound or shape to pair with it.

Etymologically, the entry records: From Ancient Greek θαλλός (thallós, “young shoot, twig”), from Proto-Indo-European *dʰelh₁- (“to bloom”). The correct English form is thallus, spelled T-H-A-L-L-U-S.

Definition

  1. 1
    An undifferentiated plant body, such as in algae.
  2. 2
    Any plant body lacking vascular tissue.

Etymology

From Ancient Greek θαλλός (thallós, “young shoot, twig”), from Proto-Indo-European *dʰelh₁- (“to bloom”).

This word in other languages

thalle(Français)Thallus(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 "thallus"?
"thallus" is spelled T-H-A-L-L-U-S. The IPA pronunciation is /ˈθæl.əs/.
What does "thallus" mean?
As a noun, "thallus" means: An undifferentiated plant body, such as in algae.
How do you pronounce "thallus"?
The IPA (International Phonetic Alphabet) transcription for "thallus" is /ˈθæl.əs/. 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 "thallus"?
From Ancient Greek θαλλός (thallós, “young shoot, twig”), from Proto-Indo-European *dʰelh₁- (“to bloom”). 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 “thallus”

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

  • The one correct English spelling is T-H-A-L-L-U-S - every other letter order is a misspelling in standard orthography.
  • Say it as /ˈθæl.əs/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • 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