WordWeb Online

1. A sign, abbreviation, letter, or character standing for words in ancient manuscripts or on coins or medals.
   "One practice was rendering an over-used, formulaic phrase only as a siglum, e.g. RIP for requiescat in pace ("Rest in Peace"), because the long-form written usage of the abbreviated phrase, itself, was rare."

Type of: character, graph, grapheme, graphic symbol

Encyclopedia: Siglum