headmaster
n.the person in charge of a school, especially a private school. This title is usually used for a man.
n.the male principal or senior administrative leader of a school, particularly within the British or private education systems.
“The headmaster gave a speech at the morning assembly.”
“Parents requested a meeting with the headmaster to discuss the new school uniform policy.”
“The headmaster maintained a strict but fair reputation, ensuring that both the academic standards and the moral character of the students remained high throughout his long tenure.”
Commonly used in British English; the female equivalent is 'headmistress', though 'headteacher' is now a more common gender-neutral alternative.
From head + master.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.