| Noun | 1. | principal - the original amount of a debt on which interest is calculateddebt - money or goods or services owed by one person to another loan - the temporary provision of money (usually at interest) | |
| 2. | principal - the educator who has executive authority for a school; "she sent unruly pupils to see the principal"chancellor - the honorary or titular head of a university | |
| 3. | principal - an actor who plays a principal roleco-star - one of two actors who are given equal status as stars in a play or film | |
| 4. | principal - capital as contrasted with the income derived from itcapital - wealth in the form of money or property owned by a person or business and human resources of economic value | |
| 5. | principal - the major party to a financial transaction at a stock exchange; buys and sells for his own accountbroker-dealer - a financial specialist who trades for his own account and so acts both as a broker and principal | |
| Adj. | 1. | principal - most important element; "the chief aim of living"; "the main doors were of solid glass"; "the principal rivers of America"; "the principal example"; "policemen were primary targets"important, of import - of great significance or value; "important people"; "the important questions of the day" | |