—v.i. 1. to fall or slip back into a former state, practice, etc.: to relapse into silence. 2. to fall back into illness after convalescence or apparent recovery.
3. to fall back into vice, wrongdoing, or error; backslide: to relapse into heresy.
—n. 1. an act or instance of relapsing.
2. a return of a disease or illness after partial recovery from it.