Definitions of grate:

• noun:   a frame of iron bars to hold a fire
• noun:   a barrier that has parallel or crossed bars blocking a passage but admitting air
• noun:   a harsh rasping sound made by scraping something
• verb:   furnish with a grate

  Example: "A grated fireplace"

• verb:   make a grating or grinding sound by rubbing together

  Example: "Grate one's teeth in anger"

• verb:   reduce to small shreds or pulverize by rubbing against a rough or sharp perforated surface

  Example: "Grate carrots and onions"

• verb:   scratch repeatedly
• verb:   gnaw into; make resentful or angry
• name:  A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #12830)