Principals

noun

1. The money originally invested or loaned, on which basis interest and returns are calculated.

   "A portion of your mortgage payment goes to reduce the principal, and the rest covers interest."

2. The chief administrator of a school.
3. The chief executive and chief academic officer of a university or college.
4. A legal person that authorizes another (the agent) to act on their behalf; or on whose behalf an agent or gestor in a negotiorum gestio acts.

   "My principal sells metal shims."

5. The primary participant in a crime.