crep·i·ta·tion \ˌ ̷ ̷ ̷ ̷ˈtāshən\noun (-s) Etymology: Late Latin crepitation-, crepitatio, from Latin crepitatus + -ion-, -io -ion 1.: the act or an instance of crepitating : a crackling noise : crackling 2.medicine: a grating or crackling sound or sensation (as that produced by the fractured ends of a bone moving against each other or as that in tissues affected with gas gangrene) < crepitation in the arthritic knee > : crepitant rale