1. two bones placed crosswise, especially as a symbol of death or danger
Usage: often used with ‘skull and’

Examples

• The pirate flag featured a skull and crossbones.
• The poison bottle was marked with crossbones as a warning.
• Crossbones appeared on the cemetery gate.
• The old map showed crossbones marking dangerous areas.
• Pirates used crossbones on their flags to intimidate enemies.
• The warning label displayed crossbones to indicate toxicity.