The act by which something is trashed.
Dumpster diving.
A tradition of throwing food, confetti, etc. over students after their final examinations.
The effacement of errors or bad actions.
The application of whitewash.
The process of whitewashing, of making over (a person or character, a group, an event, etc) so that it is or seems more white (Caucasian), for example by applying makeup to a person, or by covering over the participation of people of color in an event and focusing on only white participation.