biplane

/B AY1 P L EY0 N/
noun
  1. 1

    An airplane that has two main wings, one above the other and supported by struts

adjective
  1. 1

    Having, or consisting of, two superposed planes, aerocurves, etc.

    โ€œa biplane rudderโ€

Source: https://en.wiktionary.org/wiki/biplane