lactase
"lactase" is a 7-letter English headword indexed on PlainSpell.
The verdict
“lactase” is uncommon English (frequency #79,689 among 16,425 “L” headwords), classed as a noun. The kind of spelling people second-guess.
- #79,689
- frequency rank, English
- 16,425
- “L” headwords
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - A β-galactosidase enzyme that is involved in the hydrolysis of the disaccharide lactose into constituent galactose and glucose monomers.
| Property | Value |
|---|---|
| Headword | lactase |
| Language | English |
| Part of speech | Noun |
| Letters | 7 |
| Frequency rank | #79,689 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “lactase” sits in English frequency
Rare enough to double-check
lactase is uncommon English at frequency #79,689 among 16,425 “L” headwords, classed as anoun. Rarity is why readers land here mid-draft. Gloss: "A β-galactosidase enzyme that is involved in the hydrolysis of the disaccharide lactose into constituent galactose and glucose monomers.".
Zero misspellings are on record for lactase in our index, since its letter pattern doesn't lend itself to common typo substitutions. We don't track a confusable pairing for this entry, which tends to mean the word is visually distinctive enough to stand on its own.
Etymologically, the entry records: From lacto- + -ase. The correct English form is lactase, spelled L-A-C-T-A-S-E.
Definition
- 1A β-galactosidase enzyme that is involved in the hydrolysis of the disaccharide lactose into constituent galactose and glucose monomers.
Etymology
From lacto- + -ase.
Synonyms
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
How do you spell "lactase"?
What does "lactase" mean?
What is the origin of the word "lactase"?
Is PlainSpell free to use?
Using “lactase”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is L-A-C-T-A-S-E - 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.