シイTop 20000MeaningsNoun1. any beech tree of genus Castanopsis; chinquapin; chinkapin (Usually kana)Other readings椎しいしいExamples1キビシイ先せん生せいが生せい徒とにその種しゅの本ほんを買かうことを禁きんじました。Professor Kibishii prohibited pupils from buying that kind of book.