Syon西翁SYabbr.平方码(=square yard)abbr.主发动机偏转(=sustainer yaw)syzygetic curve合冲曲线sygamus trachea气管比翼线虫Syzygium hancein.红鳞蒲桃syphilitic node梅毒性结节Sylvest disease[医] 流行性胸膜痛systolic period收缩期syzygetic cubic合冲三次曲线Sypnoides olenan.肘析夜蛾syclinal stream向斜河Syroyechkovskiy瑟罗耶奇科夫斯基