1. Streamlined housings or pods that contain an aircraft engine and its accessories, mounted on the wings or fuselage.
Usage: plural of nacelle; aviation/aerospace term; commonly used in aircraft design and engineering
2. A small cabin or enclosed structure suspended from a balloon or airship.
Usage: historical/technical; less common modern usage

Examples

• The aircraft's twin nacelles housed powerful jet engines.
• Modern commercial jets have large nacelles that reduce aerodynamic drag.
• The nacelles on the Boeing 747 are designed for maximum fuel efficiency.
• Engineers inspected the engine nacelles for any signs of damage.
• The sleek nacelles of the new aircraft improved its overall performance.