Rollback vs. Roll Back
“Rollback” is a closed noun for an act of reducing or reversing something and is also used adjectivally; Cambridge additionally records the hyphenated adjective “roll-back.” “Roll back” is the two-word phrasal verb.
Use “rollback” as the noun for a reversal or reduction. Cambridge also records “roll-back” as an adjective variant. Use “roll back” as the phrasal verb.
Key details
Choose the right form
| If you mean / need | Use | Why |
|---|---|---|
| a reversal or reduction as a thing/event | rollback | Cambridge records the closed noun. |
| an adjective before a noun | rollback / roll-back | Cambridge documents both adjective spellings. |
| the action of reducing, reversing, or lowering | roll back | The phrasal verb is two words. |
Further guidance
Core difference
Use the documented noun or modifier form when naming a thing, result, person, or concept; use the spaced form when the words function as a verb.
Fast Test
If the expression can take ordinary verb tense or inflection in the sentence, the spaced verb form is usually the relevant choice.
Variant Boundary
Cambridge records closed “rollback” as a noun and adjective and also documents “roll-back” as an adjective variant; the phrasal verb remains “roll back.”
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- rollback — English meaning (opens in a new tab)Cambridge Dictionary · Closed rollback noun and adjective, including documented roll-back adjective variant
- roll back something — English meaning (opens in a new tab)Cambridge Dictionary · Two-word phrasal verb roll back for reducing, reversing, or lowering