Engineering is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad range of more specialized fields of engineering, each with a more specific emphasis on particular areas of applied mathematics, applied science, and types of application. See glossary of engineering. The term engineering is derived from the Latin ingenium, meaning "cleverness" and ingeniare, meaning "to contrive, devise".

Martial arts are codified systems and traditions of combat practiced for a number of reasons such as self-defense; military and law enforcement applications; competition; physical, mental and spiritual development; and entertainment or the preservation of a nation's intangible cultural heritage. Although the term martial art has become associated with the fighting arts of East Asia, it originally referred to the combat systems of Europe as early as the 1550s. The term is derived from Latin and means "arts of Mars", the Roman god of war. Some authors have argued that fighting arts or fighting systems would be more appropriate on the basis that many martial arts were never "martial" in the sense of being used or created by professional warriors.