Lockout vs. Lock Out
“Lockout” is the closed noun, while “lock out” is the two-word phrasal verb. The distinction applies both to workplace exclusion and to ordinary access contexts such as rooms, accounts, networks, and devices.
Use “lockout” as the noun for an exclusion event or state. Use “lock out” as the verb for preventing someone from entering or accessing a place, system, or device.
Key details
Choose the right form
| If you mean / need | Use | Why |
|---|---|---|
| an exclusion event/state as a noun | lockout | Cambridge records the closed noun. |
| the action of preventing entry or access | lock out | Cambridge records the phrasal verb as two words. |
Further guidance
Core difference
Use the documented noun/adjective form for the thing, result, event, or modifier; use the spaced form when the expression functions as a verb or predicate.
Fast Test
Ask what job the expression is doing in the sentence. A noun/adjective form may be closed or hyphenated by dictionary convention; a verb or predicate normally keeps the words separate.
Variant Boundary
Cambridge distinguishes the closed noun “lockout” from the phrasal verb “lock out.”
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.
- Lockout — Cambridge Dictionary (opens in a new tab)Cambridge Dictionary · Closed noun “lockout” for exclusion from a workplace and related exclusion contexts
- Lock someone out — Cambridge Dictionary (opens in a new tab)Cambridge Dictionary · Two-word phrasal verb “lock out” for preventing entry or access