The term "thoraxes" refers to the plural form of thorax, which is the part of the human body located between the neck and the abdomen. Antonyms for this word include neck, abdomen, and head. These terms are all different parts of the body that are located at the opposite ends of the thorax. Some other antonyms for thoraxes may include arms, legs, hands, and feet, which are all limbs of the body. Additionally, antonyms may include non-anatomical terms such as exterior, surface, and skin, which are all ways to describe the outside of the body rather than its internal structure.