midriff
When the stomach is partially exposed by clothing.
Use this tag when there are regular clothes above (e.g. a crop top) and below (e.g. pants) the stomach, but the stomach is bare or visible beneath see-through clothing. The clothing over and above must not be underwear or a bikini.
Don't use this tag if the character is topless, bottomless, nude, or wearing underwear only or a bikini only. It may be used for underwear worn as outerwear, such as for sports bras, camisoles or tank tops worn with panties, or other similar outfits.
Often goes with navel and stomach.