principal

Sense 1 noun

the original amount of a debt on which interest is calculated

Sense 2 noun

the educator who has executive authority for a school

she sent unruly pupils to see the principal

Sense 3 noun

an actor who plays a principal role

Sense 4 noun

capital as contrasted with the income derived from it

Sense 5 noun

(criminal law) any person involved in a criminal offense, regardless of whether the person profits from such involvement

Sense 6 noun

the major party to a financial transaction at a stock exchange; buys and sells for his own account