biplane

adj

1. (not-comparable)Composed of, or relating to, two planes (flat surfaces extending infinitely in all directions).

   “biplane angiography”

   “The left apical 4-chamber image is used for one measurement and for a “biplane” estimate (that averages values from orthogonal planes), either the right parasternal long-axis image (the authors' preference) or the left apical 2-chamber view (shown here) is also measured. […] Either a biplane (Simpson) method of discs or a 3D volumetric rendering is used for LV volume measurements in human echocardiography laboratories.”

2. (not-comparable)Having, or consisting of, two superposed planes, aerocurves, etc.

   “a biplane rudder”

noun

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

verb

1. (intransitive, rare)To fly in a biplane.

   “For an unforgettable experience, try llama trekking along a gentle trail in the White River National Forest, […] There also are sky-high balloon rides, biplaning, hang gliding, paragliding and plenty of wilderness paths for hiking.”