Turn Signal vs. Indicator
The two terms are regional counterparts in the vehicle-light sense. “Indicator” also has many broader meanings, so the equivalence should not be generalized beyond vehicles.
For the flashing vehicle light that shows an intended turn, use “turn signal” in US English and “indicator” in UK English.
Key details
Choose the right form
| Meaning / context | Use | Decision |
|---|---|---|
| flashing turn light in US-oriented wording | turn signal | Use the American term. |
| same vehicle light in UK-oriented wording | indicator | Use the British term. |
| non-vehicle measure, sign, or device | indicator may have another sense | Do not substitute “turn signal.” |
Quick tests
Decision test
Are you naming the flashing light on a vehicle that shows intended turning direction?
If yes: Use “turn signal” in US-oriented wording and “indicator” in UK-oriented wording.
If no: For other meanings of “indicator,” use the term appropriate to that context.
Caveat: Keep the comparison to the vehicle-light sense; “indicator” is a much broader noun.
Examples
Use your turn signal before changing lanes.
“Turn signal” is standard US automotive wording.
The driver switched on the left indicator.
“Indicator” is standard UK automotive wording.
The gauge is an indicator of fuel level.
This broader “indicator” sense is unrelated to turn signals.
Further guidance
Core difference
Use the American term.
Fast Test
Use “turn signal” in US-oriented wording and “indicator” in UK-oriented wording. For other meanings of “indicator,” use the term appropriate to that context.
Usage Boundary
Keep the comparison to the vehicle-light sense; “indicator” is a much broader noun.
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.
- turn signal (opens in a new tab)Cambridge University Press · Turn signal is marked US for the flashing vehicle light showing intended direction; Cambridge gives UK indicator as the counterpart.
- indicator (opens in a new tab)Cambridge University Press · In the vehicle-light sense, indicator is marked UK with US signal/turn signal as counterparts.