No, a “widebody” does not refer to an overweight person…it means a commercial aircraft with 2 aisles instead of 1. Widebody airliners always seem more comfortable to me than single-aisle aircraft.
A Boeing 777 is an example of a widebody airliner.
The Wandering Aramean has created a tool to show which routes in the United States will be flown by widebody aircraft. Only about 35 airports in the US are served by widebody airliners.
Because they are “fatter” than narrowbody aircraft, widebodies cause more air turbulence when they take off and land. This turbulence has the possibility of disturbing the aircraft that follows the widebody down the runway, so air traffic controllers have to allow extra time after a widebody takes off or lands.
The air traffic controller term for a widebody aircraft is “heavy.”