A fine-grained metamorphic rock that splits into thin, smooth-surfaced layers. A piece of this rock cut for use as roofing or surfacing material or as a writing surface. A writing tablet made of a similar material. A record of past performance or activity: start over with a clean slate. A list of the candidates of a political party running for various offices. A dark or bluish gray to dark bluish or dark purplish gray. Made of a fine-grained metamorphic rock: a slate roof. Of the color slate. To cover (a roof, for example) with slate. To put on a list of candidates. To schedule or designate: Our professor has slated the art history lecture for Thursday afternoon; was slated to direct the studio's next film.