belly button 
noun informal
A person’s navel.Squeeze your buttocks, draw your belly button to your spine and tilt your pelvis....
- She is nude and the image shows her body from her belly button to her knees.
- Most want ear or nose piercings, although a few prefer to have their belly button or genitals pierced.
- binding post
- binding site
- bindlestiff
- bind off
- bind (or tie) someone hand and foot
- bind someone hand and foot
- bindweed
- bine
- bin-end
- Binet, Alfred
- Binet test
- Binet–Simon scale
- Binet–Simon test
- bing
- Bing cherry
- binge
- binge-and-purge
- binge-drink
- binge drinker
- binge drinking
- binge-eat
- binge eater
- binge eating
- binge-eating disorder
- binger