Definitions:

1. A streamline housing or tank for something on the outside of an aircraft or motor vehicle. NOUN
   • Workers at the plant connect the 'nacelles' to the engines.
2. The cover that holds engines, fuel, and equipment on an aircraft but is separate from the fuselage or main body of the aircraft. NOUN
   • The large fans at the front of today's jet engines are entirely encased in a protective pod called a 'nacelle'.
3. The outer casing of an aircraft engine. NOUN
   • The design of the aircraft has been modified and the engine 'nacelles' now encase the entire engine.

Synonyms:

• box
• crate
• enclosure