1. An argument or form of reasoning in which two statements or premises are made and a logical conclusion drawn from them: All mammals are warm-blooded (major premise); whales are mammals (minor premise); therefore, whales are warm-blooded (conclusion).
2. Reasoning from the general to the particular; deductive logic: A syllogism can be an instance of subtle, tricky, or specious reasoning; or one that seems to be true but is actually false or deceptive.