principal
nounUK /ˈprɪn.sə.pəl/
US /ˈprɪn.sə.pəl/
The principal is the person in charge of a school.
The principal greeted the students at the school gate.
OTHER MEANINGS
2. The most important or main thing.
The principal reason for the delay was the heavy rain.
3. A sum of money that is borrowed or invested, not including interest.
She paid back the principal on her loan first.
4. A main person in a play, film, or piece of music.
He is the principal in the new musical.