脇腹

1. Origins, structure, and basic meaning

• Structure: The body-part noun 脇腹 (わきばら) denotes the side or flank of the torso between the ribs and waist.
• Basic usage: It can be the subject of pain in 脇腹が痛くなる or the object struck in 脇腹を打つ.

2. Common pitfalls and similar expressions

• The side of the torso
  • It is the side area between the arm and waist, not the whole abdomen or one rib.