exothermic
"exothermic" is a 10-letter English headword indexed on PlainSpell.
The verdict
“exothermic” is uncommon English (frequency #69,836 among 2,246 “E” headwords), classed as an adjective. The kind of spelling people second-guess.
- #69,836
- frequency rank, English
- 2,246
- “E” headwords
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - That releases energy in the form of heat.
Corpus desk
Index EN-exothermic · exothermic · English
exothermic · rank #69,836 · 0 variants · 0 confusables
- FREQ-RARE #69,836
- LEN-MEGA 10 letters
- VOW-4 4 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-MID 2,246
- PHOTO-FINISH expansionary
Nearest frequency peer: expansionary (+1 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.
Long-tail ranks near “exothermic”
Sparse band: bars invert rank so rarer forms read shorter
- exacerbation
exacerbation
30,170 corpus weight
- excitability
excitability
30,169 corpus weight
- existance
existance
30,167 corpus weight
- exothermic
exothermic
30,165 corpus weight
- expansionary
expansionary
30,164 corpus weight
- expensively
expensively
30,162 corpus weight
What this shows Long-tail view: where “exothermic” sits against similarly uncommon English ranks.
| Property | Value |
|---|---|
| Headword | exothermic |
| Language | English |
| Part of speech | Adjective |
| Letters | 10 |
| Frequency rank | #69,836 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “exothermic” in English
Rare enough to double-check
exothermic is uncommon English at frequency #69,836 among 2,246 “E” headwords, classed as anadjective. Rarity is why readers land here mid-draft. 3 senses are on record.
The misspelling generator found no plausible variants for exothermic, a sign its spelling follows regular English conventions. 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 French exothermique, from exo- (“outside”) + thermique (“of heat”), both ultimately from Ancient Greek. By surface analysis, exo- + -thermic. The correct English form is exothermic, spelled E-X-O-T-H-E-R-M-I-C.
Definition
- 1That releases energy in the form of heat.
- 2That releases heat during its formation, and absorbs it during its decomposition.
- 3Of an animal: whose body temperature is regulated by external factors; cold-blooded.
Recorded use
Wiktionary exampleThese source excerpts show how exothermic appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
These can be differentiated on a thermal scan where an endothermic transition indicates enantiotropes and an exothermic transition indicates monotropes.
Etymology
From French exothermique, from exo- (“outside”) + thermique (“of heat”), both ultimately from Ancient Greek. By surface analysis, exo- + -thermic.
Synonyms
Antonyms
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); 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
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Similar English words by spelling shape
Same letter count and similar misspelling depth for "exothermic", not the corpus desk frequency band.
Same letter count
Frequency-ranked English headwords with 10 letters (nearest by frequency rank).