English UsageComparison guide

Standby vs. Stand By

“Standby” is the usual closed noun/adjective in Cambridge, with “stand-by” documented as a Business English variant. “Stand by” is the two-word phrasal verb.

Quick answer

Use “standby” as the usual closed noun or adjective for something ready for use; Cambridge Business English also records “stand-by.” Use “stand by” as the phrasal verb when someone waits ready, supports someone, or maintains a position.

Key details

Confusion Familyword-boundary
Noun Variant ScopeCambridge records closed “standby” as a noun/adjective, documents “stand-by” as a Business English variant, and records “stand by” as the phrasal verb.
Rule Familyorthographic-boundary
Termsstandby, stand-by, stand by

Choose the right form

Decision table for Standby vs. Stand By
If you mean / needUseWhy
a person, thing, state, ticket, or modifier that is ready if neededstandbyCambridge records the closed noun/adjective.
a documented Business English noun/adjective variantstand-byCambridge records the hyphenated variant.
the verb action of waiting ready or supportingstand byCambridge records the phrasal verb as two words.

Further guidance

Core difference

Use the documented noun or modifier form when naming a thing, result, event, 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 “standby” as a noun/adjective, documents “stand-by” as a Business English variant, and records “stand by” as the phrasal verb.

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.

  1. STANDBY — English meaning (opens in a new tab)Cambridge Dictionary · Closed noun/adjective “standby” and documented Business English “stand-by” variant
  2. STAND BY SOMEONE — English meaning (opens in a new tab)Cambridge Dictionary · Two-word phrasal verb “stand by”

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