1. relating to or involving the destruction of all life or all of humanity; capable of causing total annihilation
Usage: formal; often used in academic or philosophical contexts discussing existential threats

Examples

• The scientist warned that unchecked climate change could have omnicidal consequences for civilization.
• Nuclear war represents an omnicidal threat that humanity must work to prevent.
• The philosopher discussed omnicidal scenarios in her book on existential risk.
• Some environmentalists argue that certain industrial practices pose omnicidal dangers to ecosystems.
• The film depicted an omnicidal pandemic that wiped out most of the world's population.