a rotary engine that is a four-stroke internal-combustion engine without reciprocating parts
motor that converts thermal energy to mechanical work
something used to achieve a purpose
a wheeled vehicle consisting of a self-propelled engine that is used to draw trains along railway tracks
electrical converter consisting of a synchronous machine that converts alternating to direct current or vice versa
a road junction at which traffic streams circularly around a central island
describing a circle; moving in a circle
an instrument or machine that is used in warfare, such as a battering ram, catapult, artillery piece, etc.