principal

adjective

1
most important element
the chief aim of living
the main doors were of solid glass

1
the major party to a financial transaction at a stock exchange; buys and sells for his own account
2
the educator who has executive authority for a school
she sent unruly pupils to see the principal
3
(criminal law) any person involved in a criminal offense, regardless of whether the person profits from such involvement
4
an actor who plays a principal role
5
capital as contrasted with the income derived from it
6
the original amount of a debt on which interest is calculated

Also useful for “principal”:Unscrambler— Rearrange the letters in “principal”