fairing
v.a part of a vehicle that covers the space between the wheels or the engine. It is usually made of plastic and helps the vehicle look smooth and move through the air more easily.
v.a structural component of an aircraft or vehicle that covers the gap between the fuselage and the wings or between the wheels. Often constructed from lightweight composite materials to reduce aerodynamic drag.
“The car's front fairing is made of clear plastic.”
“The mechanic replaced the damaged fairing after the motorcycle collided with a curb.”
“Modern aircraft utilize a complex network of composite fairings to streamline the fuselage, ensuring that the airflow remains laminar and reducing the overall fuel consumption during long-haul flights.”
“The telescope is already enclosed inside Falcon Heavy's protective fairing, the shell that surrounds a spacecraft during launch and shields it from aerodynamic forces and the atmosphere.”
“NASA’s Roman Space Telescope is now enclosed inside its Falcon Heavy fairing and nearly ready for launch.”
From fair (“community gathering, market”). In the sense of food, because cakes and sweets were sold at fairs.
From fair (“to smoothen or even a surface”).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.