The term 'MIDDLE PART' can be described by three crossword solutions: ABDOMEN (7 letters), WAIST (5 letters), and ALTO (4 letters). The ABDOMEN is the part of the body between the chest and the pelvis, and it contains many of the body's vital organs. The WAIST is the narrowest part of the torso, located between the rib cage and the hips. Finally, ALTO is a musical term referring to the second-highest vocal range in choral music. All three of these terms refer to the middle part of the body.