A theoretical type of antimatter rocket which uses proton-antiproton fuel, and magnetic rocket funnels to direct the π-on exhaust. The pi meson particles are created by the matter-antimatter annihilation of protons and antiprotons.

Cancer productus, common along the western coast of North America / Grapsus grapsus, common along the western coast of South America

A proposed form of rocket that would use antimatter as direct or indirect propellant

(figuratively) To be isolated from knowledge of current events.

plural of road captain

Synonym of uncool.

The captain of a bicycle racing team, who sets the pace. / (motorcycle club) An experienced rider who organizes and marshals the motorcycle club on the road.

(archaic) Synonym of roarer (“brawling young man”)

plural of roaring boy

(computer games, chess) The game of chess involving a robot able to play with physical pieces autonomously, i.e. without human guidance.