principal >> /ˈprɪnsəpəl/
Definition: [noun] The person with the highest authority or most important position in an organization, institution, or group.
Example: a design consultancy whose principal is based in San Francisco
Definition: [noun] A sum of money lent or invested, on which interest is paid.
Example: the winners are paid from the interest without even touching the principal
Definition: [noun] A person for whom another acts as an agent or representative.
Example: stockbrokers in Tokyo act as agents rather than as principals
Definition: [noun] The person directly responsible for a crime.
Example: Complicity often involves the accomplice in words or deeds prior to the principal's crime.
Definition: [noun] A main rafter supporting purlins.
Example: The truss principal extends from below the plate to the ridge.
Definition: [noun] An organ stop sounding a main register of open flue pipes typically an octave above the diapason.
Example: all the principals are on one manual
Definition: [adjective] First in order of importance; main.
Example: the country's principal cities
Definition: [adjective] (of money) denoting an original sum invested or lent.
Example: the principal amount of your investment