Lockdown vs. Lock Down
“Lockdown” is the noun for an official restriction or state of restricted movement, while “lock down” is the corresponding phrasal verb. Sentence function determines the spacing.
Use “lockdown” as the noun and “lock down” as the verb.
Key details
Choose the right form
| Meaning / situation | Form / construction | Decision |
|---|---|---|
| noun naming restriction/state | lockdown | Use the closed noun. |
| verb meaning impose restriction/secure | lock down | Use the two-word verb. |
Quick tests
Meaning / construction test
Is the expression functioning as a noun naming the event or state?
If yes: Use “lockdown.”
If no: Use “lock down” when it is the verb.
Examples
The building went into lockdown.
The closed form is a noun.
They will lock down the system tonight.
The open form is a verb.
The team locked down access after the alert.
Inflection confirms the two-word verb.
Further guidance
Core difference
Use one-word “lockdown” for the noun; use two-word “lock down” when the expression functions as the verb.
Fast Test
If the sentence can inflect the verb—“locked down,” “locking down”—use the two-word verb. If it names the restriction or state, use “lockdown.”
Usage Boundary
This is a grammatical word-boundary distinction, not a regional spelling choice.
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.
- lockdown noun — Oxford Advanced Learner’s Dictionary (opens in a new tab)Oxford University Press · Direct evidence for lockdown as a one-word noun naming an official movement restriction.
- lock down phrasal verb — Oxford Advanced Learner’s Dictionary (opens in a new tab)Oxford University Press · Direct evidence for lock down as a two-word phrasal verb.