on the sly
"on-the-sly" is a 8-letter English headword indexed on PlainSpell.
The verdict
“on the sly” is uncommon English (outside the top frequency list), classed as an adverb. The kind of spelling people second-guess.
- Unranked
- below top-frequency English
- 10
- letters
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Slyly, in an inconspicuous manner, so as not to be seen; secretly; stealthily.
Corpus desk
Index EN-on-the-sly · on the sly · English
on the sly · unranked · 0 variants · 0 confusables
- FREQ-UNRANKED Unranked
- LEN-MEGA 10 letters
- VOW-3 3 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-THIN "O" 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.
| Property | Value |
|---|---|
| Headword | on the sly |
| Language | English |
| Part of speech | Adverb |
| Letters | 10 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “on the sly” in English
Rare enough to double-check
on the sly is uncommon English outside the top frequency list, classed as anadverb. Rarity is why readers land here mid-draft. Gloss: "Slyly, in an inconspicuous manner, so as not to be seen; secretly; stealthily.".
No misspelling variants are generated for on the sly in our index, since its letter sequence doesn't invite the usual edit-distance slips. This entry stands alone in our confusable dataset, which typically means the spelling is too distinctive to be mistaken for another word.
This entry carries no recorded etymology, so its spelling is easiest to reason about phoneme by phoneme, absent a documented history. The correct English form is on the sly, spelled O-N- -T-H-E- -S-L-Y.
Definition
- 1Slyly, in an inconspicuous manner, so as not to be seen; secretly; stealthily.
Recorded use
Wiktionary examplesThese source excerpts show how on the sly appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.
This diversion was enjoyed on the sly, and unknown to the ladies of the house.
He was working for us on the sly at the Herald-Traveler-Record-American (before it shortened its topheavy name), then as now a reactionary, homophobic rag. Evidently he placed himself at some risk to help us, I learned later, because he was threatened with dismissal for his unauthorized use of the typesetter.
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). See the methodology for how each field is sourced and updated.