Kirchner (surname)
Kirchner is old-fashioned German for "Küster" (caretaker of the sacristy). As such it was included in the Duden, the leading German language dictionary until the 1990s. Today the word "Kirchner" is not often used in that way, and has been replaced by "Küster" although there are regional differences.
The word "Kirchner" is derived from the word "Kirche" (church), which in turn is based on the Greek "kyriakos" (belonging to the Lord, i.e. God). "Kyriakos" in turn is based on the Greek word "kyrios" (Lord). Cognates can also be found in other northern European languages (church, kerk, kirkko, kirkka, crkva, цeрковь).
The ending -er is common in German family names and usually indicates that a family name is based on a profession.