- the lower abdomen; posterior ventral area, as of an animal's body.
- the lower surface of an object; underside: the underbelly of an airplane.
- a vulnerable area; weak point: an attack on the soft underbelly of Europe.
- a dark, seamy, often hidden area or side: a police officer continually exposed to the underbelly of society.
- the part of an animal's belly nearest to the ground
- a vulnerable or unprotected part, aspect, or region
