Family name origins & meanings
- German (also Küster) : status name for a sexton or churchwarden, Middle High German kuster (Late Latin custor ‘guard’, ‘warden’). The umlaut of the modern form is due to association with other agent nouns in -er, from Old High German -āri (Latin -arius).
- Slovenian (Kušter) : nickname for a person with disheveled hair, from kušter ‘tuft of hair’, ‘towhead’.