A secondary or assistant master, often used in educational or organizational contexts to denote someone who assists a primary master.

सहायक मुख्य

English Usage: The sub master was responsible for overseeing the students during the absence of the headmaster.

Hindi Usage: सहायक मुख्य ने प्रधानाचार्य की अनुपस्थिति में छात्रों की देखरेख की।