English▸ noun a streamlined housing or tank for something on the outside of an aircraft or motor vehicle:
a gray aircraft with NAVY painted on the engine nacelles.
▪ the outer casing of an aircraft engine.
▪ the car of an airship.
– ORIGIN early 20th century (originally denoting the car of an airship): from French, from late Latin navicella, diminutive of Latin navis ‘ship’.