di·he·dral 
(dī-hēdrəl)
(dī-hēdrəl)adj.
Mathematics
Mathematics
1. Formed by or having two plane faces; two-sided.
2. Relating to, having, or forming a dihedral angle.
n.
1. Mathematics
a. A dihedral angle.
b. A dihedral group.
2. Aeronautics The upward or downward inclination of an aircraft wing from true horizontal.