biplane

名词 biplane:

1. old fashioned airplane; has two wings one above the other

bi.plane

n.（名词）
An airplane having two pairs of wings fixed at different levels, especially one above and one below the fuselage.
双翼飞机：有两片机翼安在不同水平线的飞机，尤指一在机身上方，一在机身下方