skull and crossbones

American  

noun

1. a representation of a front view of a human skull above two crossed bones, originally used on pirates' flags and now used as a warning sign, as in designating substances as poisons.

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skull and crossbones British  

noun

1. a picture of the human skull above two crossed thighbones, formerly on the pirate flag, now used as a warning of danger or death

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skull and crossbones Cultural  

1. A picture or outline of a human skull and two crossed arm or leg bones. Pirate ships are supposed to have used the skull and crossbones on their flags. (See also Jolly Roger.)

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Etymology

Origin of skull and crossbones

First recorded in 1820–30

Example Sentences

From Nepal to Peru, Morocco and Madagascar, brandishing the symbol of a skull and crossbones in a straw hat, Gen Z protests across the world stood up to authorities in 2025, even toppling two governments.

From Barron's

"We chose a terrifying looking skull and crossbones off the wall because we were marines and skulls and crossbones are pretty standard military thing," he said.

From BBC

“We chose a terrifying looking skull and crossbones off the wall because we were marines and skulls and crossbones are pretty standard military thing,” he said.

From Salon

A vehement nonsmoker, he kept in his office a cigarette box adorned with a skull and crossbones, to demonstrate their danger.

From Los Angeles Times

The next day, Mr. Ihnat published a message on Facebook that included emojis representing a skull and crossbones, three planes, and a picture of a Patriot system.

From New York Times