Definitions of girdle:

• noun:   a band of material around the waist that strengthens a skirt or trousers
• noun:   an encircling or ringlike structure
• noun:   a woman's close-fitting foundation garment
• verb:   put a girdle on or around
• verb:   cut a girdle around so as to kill by interrupting the circulation of water and nutrients

  Example: "Girdle the plant"