The Chinese word for headmaster is
校长

xiào zhǎng

Chinese Definition

headmaster
1. 校长
Components
校
1. school; college; university
軍校 - military school
2. (military) field officer
3. (historical) horsekeeper official
4. to proofread; to check; to compare
5. (printing) proof
6. (Cantonese) to adjust
校gaau3 返啱隻錶 - to adjust a watch to the correct time
长
1. Simplified form of 長

校長
1. n. principal (of a school); headteacher
她被任命為wéi 校長zhǎng。 - She was appointed principal.
接下來，有請我們的校長zhǎng 發表演講。 - Next, we invite our principal to give a speech.
2. n. president (of a school or university)
3. n. (ancient China) leader of a soldier division