Any material considered crucial to national security concerns and military applications. Examples include natural resources, such as oil; alloys, such as steel, aluminum, and titanium; and composite materials, such as advanced plastics, polymers and ceramics.

A material in its unprocessed, natural state considered usable for manufacture. / (figuratively) Any physical product serving as input to a factory or other installation which processes it.

The branch of logic that focuses on the content of reasoning.

A substance, natural or man-made, which is intrinsically dangerous or otherwise poses a safety hazard. Examples are materials which are explosive, poisonous, chemically active (including acids and other corrosives), radioactive, or biologically active (including human blood and other medical waste).

(law) a breach of contract sufficiently serious to destroy the contract / a breach of a treaty which releases other parties from any obligation under it

(philosophy) The concept of reality in which material things are in the constant process of change brought about by the tension between conflicting or interacting forces, elements, or ideas.

(logic) An implication as defined in classical propositional logic, leading to the truth of paradoxes of material implication such as Q⊢P→Q, to be read as "any proposition whatsoever is a sufficient condition for a true proposition".

Essential components of a device, reaction, etc. / A radioactive material

A textile of silk and wool, soft and flexible, usually with oriental designs, used for women's dresses.

plural of active material