Principal is a word with multiple meanings depending on the context:
1. In education: The principal is the head of a school.
2. In finance: The principal refers to the original sum of money invested or loaned.
3. In law: A principal is a person who authorizes another to act on their behalf.
4. In general usage: Principal can mean first in order of importance.
5. In music: The principal is the leading performer in a section of an orchestra.