腹 (fù): abdomen; stomach; belly

He persists in doing one hundred sit-ups every day, and his abdominal muscles are getting firmer and firmer.

After finishing the meal, I feel a bit bloated in my abdomen; maybe I ate too quickly.

The doctor gently pressed his abdomen and asked him whether it hurt here.

After five months of pregnancy, her abdomen clearly bulged, and she began to walk more slowly.