(UK, Australia, historical) A convict assigned to work as a servant for a free settler (either a male or female convict, and either a male or female settler).
The term convict was considered an insult in early colonial Australia (reference: Robert Hughes, The Fatal Shore, 1987, paperback ISBN 1-86046-150-6, page xi.). Assigned servant was one of several euphemisms; see convict for others.
English Wiktionary. Available under CC-BY-SA license.