The fly agaric mushroom.

plural of deadly amanita

(military) In nuclear weapons strategy: encouraging deterrence by guaranteeing an immediate, automatic, and overwhelming response to an attack, even if the command-and-control infrastructure has been damaged by the enemy's first strike.

plural of deadly carrot

Any of the genus Thapsia of poisonous plants in the family Apiaceae.

(Catholicism) The cardinal sins enumerated by Thomas Aquinas in the 13th century: pride (or vanity), envy, gluttony, greed (or avarice), lust, sloth, and wrath (or anger).

(object-oriented programming, humorous) The diamond problem.

plural of deadly diamond of death