The position of an aircraft or aircraft part when its lateral axis and some chosen longitudinal axis are both horizontal.
Early 20th century; earliest use found in Horatio Barber (b. 1875).
英语词典包含464360条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。