Definition of new chum in English:

new chum

Pronunciation /ˈnjuː ˌtʃʌm/

noun

informal Australian, New Zealand
  • 1A newly arrived immigrant; a new arrival to an area. Now chiefly historical.

  • 2A novice, newcomer, or beginner; a person inexperienced in a particular occupation, activity, etc.

adjective

informal Australian, New Zealand
  • That is a newly arrived immigrant, novice, etc. Also: characteristic of such a person; raw, inexperienced, unsophisticated, amateurish.

Origin

Early 19th century (in an earlier sense). From new + chum.