The word "principal" means the most important or main person or thing in a group, like the head of a school or the main amount of money in a loan. Full definition
Her career path through the years has brought her to her current status of principal of the upper and lower school, which will eventually be a full K - 12 system. (fourcornersupperschool.org)
Minimum balance requirements apply to average daily balance (amount of principal in account each day). (sffcu.dd-site.com)
He served as principal investigator for the first rigorous, nationwide examination of the effectiveness of nonprofit charter - school management organizations. (edimpactlab.com)