Skull and crossbones

An image of a human skull above two crossed bones, used as an emblem of death, danger, poison, or piracy.

Memento mori: An artistic or literary reminder that death is inevitable. The emblem turns mortality into a compact, recognizable image.
Globally Harmonized System of Classification and Labelling of Chemicals: A United Nations system for classifying and communicating chemical hazards. Its labels use a skull pictogram to warn of acute toxicity.
Piracy in the Caribbean: Pirate activity in the Caribbean and nearby waters, especially during the seventeenth and eighteenth centuries. Pirate flags helped make the skull and crossbones an enduring symbol of piracy.
Biohazard symbol: A warning symbol for biological substances that pose a health risk. Unlike the skull and crossbones, it identifies biological hazards rather than general acute toxicity.
Jolly Roger: A pirate flag, often bearing a skull and crossbones, used to threaten captured ships. This name identifies the emblem's best-known use in pirate flags.
Poison control center: A service that provides expert advice about exposure to potentially harmful substances. The emblem helps identify products whose exposure may require urgent advice.
Danse Macabre: A medieval artistic tradition depicting death leading people from every social class to the grave. Its imagery helped establish skeletons and skulls as legible signs of death.
Radiation warning symbol: A trefoil-shaped sign warning of ionizing radiation. Its distinctive geometry warns of radiation, not poison or mortality generally.
Poison: A substance that can cause illness or death through chemical action in an organism. The skull and crossbones became a familiar warning symbol for poisonous substances.
Flag of the United States Marine Corps: The official flag of the United States Marine Corps, displaying its emblem on a scarlet field. A skull and crossbones appears in the Corps' Eagle, Globe, and Anchor emblem.

Linked from 2 pages