Meaning of PRINCIPAL in English

(MAIN) [adjective] [before noun; not gradable] - first in order of importanceIraq's principal export is oil.He was principal dancer at the Dance Theatre of Harlem.The principal reason for moving was to find a house in a more peaceful neighbourhood.(UK) A principal boy is the most important male character in a pantomime (= musical play for children), who is usually played by a woman.

Cambridge English vocab.      Кембриджский английский словарь.