A Tombstone

1. A headstone marking a person's grave. Synonyms: headstone, gravestone
2. (mathematics) The symbol "∎" marking the end of a proof.Synonym: halmos
3. (computing, Microsoft Windows) A marker that takes the place of deleted data, allowing for replication of the deletion across servers etc.
4. (computing) A crashdump.
5. (cardiology) An unusual morphological feature on an electrocardiogram indicative of acute myocardial infarction, characterized by a massive ST elevation.
6. (journalism) A printed advertisement in a newspaper or magazine, typically having unadorned centered text in black and white, enclosed in a simple box.