back up
"back-up" is a 6-letter English headword indexed on PlainSpell.
The verdict
“back up” is outside the top-ranked English vocabulary, used as a verb - the kind of word writers most often double-check.
- Unranked
- below top-frequency English
- 7
- letters
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - To move backwards, especially for a vehicle to do so.
| Property | Value |
|---|---|
| Headword | back up |
| Language | English |
| Part of speech | Verb |
| Letters | 7 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “back up” sits in English frequency
Spelling & Dictionary Insight
The English entry for back up is 7 letters long, classified as a verb. It sits outside the most-frequent rank tiers, which is often why uncommon words generate more spelling variants per reader. Wiktionary records 12 distinct senses for this headword, so context determines which meaning a reader should apply.
The misspelling generator found no plausible variants for back up, a straightforward case of a spelling with little room for common typos. It is not paired with a close-neighbour confusable in our dataset, since no other headword is close enough in sound or shape to pair with it.
No explicit etymology string is stored for this entry, so its spelling is best explained by sound-to-letter mapping rather than etymology. The correct English form is back up, spelled B-A-C-K- -U-P.
Definition
- 1To move backwards, especially for a vehicle to do so.
- 2To move a vehicle backwards.
- 3To undo one's actions.
- 4To reconsider one's thoughts.
- 5To copy (data) so that it can be restored if the main copy is lost.
- 6To provide support or the promise of support to.
- 7For the non-striker to take a few steps down the pitch, in preparation to taking a run, just as the bowler bowls the ball.
- 8For a fielder to position himself behind the wicket (relative to a team-mate who is throwing the ball at the wicket) so as to stop the ball, and prevent overthrows.
- 9To halt the flow or movement of something.
- 10To fill up because of a backlog.
- 11To run a printing press in reverse.
- 12If a property backs up to another property, that means it abuts or shares a border with another property.
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.
Frequently Asked Questions
How do you spell "back up"?
What does "back up" mean?
What language does "back up" come from?
Is PlainSpell free to use?
Using “back up”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is B-A-C-K- -U-P - every other letter order is a misspelling in standard orthography.
- Browse more English words and confusable pairs in the same reference. English words
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.