principal

principal (http://definr.com/principal)

     adj : 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" [syn: chief(a), main(a), primary(a),
            principal(a)]
     n 1: the original amount of a debt on which interest is
          calculated
     2: the educator who has executive authority for a school; "she
        sent unruly pupils to see the principal" [syn: {school
        principal}, head teacher, head]
     3: an actor who plays a principal role [syn: star, lead]
     4: capital as contrasted with the income derived from it [syn:
        corpus, principal sum]
     5: the major party to a financial transaction; buys and sells
        for his own account [syn: dealer]