Definitions of scratch:

• noun:   an indication of damage
• noun:   informal terms for money
• noun:   poor handwriting
• noun:   dry mash for poultry
• noun:   a depression scratched or carved into a surface
• noun:   an abraded area where the skin is torn or worn off
• noun:   a harsh noise made by scraping
• verb:   cut the surface of; wear away the surface of
• verb:   scrape or rub as if to relieve itching

  Example: "Don't scratch your insect bites!"

• verb:   cause friction

  Example: "My sweater scratches"