biplane

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.

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

a biplane rudder

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

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.