S: (v) chew, masticate, manducate, jaw (chew (food); to bite and grind with the teeth) "He jawed his bubble gum"; "Chew your food and don't swallow it!"; "The cows were masticating the grass"
S: (v) grate, grind (make a grating or grinding sound by rubbing together) "grate one's teeth in anger"
S: (v) change (undergo a change; become different in essence; losing one's or its original nature) "She changed completely as she grew older"; "The weather changed last night"