校长
xiàozhǎng · HSK 2
principal
🏫 校 = school + 长 = chief/head — literally school-chief
校 means school (think 学校) and 长 means chief or elder. Stacked together they name the person in charge of a school: principal or headteacher. Same 长 appears in 队长 (team leader) and 市长 (mayor).
长 — pictograph of long-haired person with cane
Originally a pictograph showing a person with long, flowing hair leaning on a cane, representing an elder. The meaning extended from 'long hair' to 'long' in general, and also to 'elder' or 'to grow' (read zhǎng). The modern form 长 is a simplification of the traditional 長.