red light

¹ American  

noun

1. a red lamp, used as a traffic signal to mean “stop.”

2. an order or directive to halt an action, project, etc..

   There's a red light on all unnecessary expenses.

3. a children's running game in which players must stop when “Red light!” is called.

4. a signal of danger; warning.

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red-light ² American  

[red-lahyt] / ˈrɛdˈlaɪt /

verb (used with object)

red-lighted, red-lighting

1. Informal. to stop or deter by means of or as if with a red light.

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red light British  

noun

1. a signal to stop, esp a red traffic signal in a system of traffic lights

2. a danger signal

3. an instruction to stop or discontinue

4. 1. a red lamp in a window of or outside a house indicating that it is a brothel

   2. ( as modifier )

      a red-light district

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Etymology

Origin of red light¹

First recorded in 1840–50

Origin of red-light²

First recorded in 1895–1900

Example Sentences

For investors, Wall Street’s optimism is a flashing red light, notes DataTrek co-founder Nicholas Colas, who flagged the FactSet report in his newsletter Monday, calling it, “the most disturbing graph we saw this entire weekend.”

From Barron's

The “personal computers” of the day were hobbyists’ kits, contraptions that arrived in pieces, with output displays that were limited to blinking red lights.

From Los Angeles Times

A green light and a red light at the same intersection.

From Los Angeles Times

Writing on X, Robert A. Pape, a longtime scholar of terrorism, posted: “After tracking terrorism for 25 years, this is a flashing red light — as bright as I’ve seen prior to a serious attack.”

From Los Angeles Times

“I didn’t ask a man to rear-end my car at a red light.”

From The Wall Street Journal

Related Words

• traffic signal