dihedral

noun

1. An angle between two plane surfaces
2. The upward slope of an aircraft's wing
3. The angle between pairs of chemical bonds separated by a third bond

adj

1. (not-comparable)Consisting of, relating to or contained between two plane surfaces.

   “dihedral angle”

2. (not-comparable)Having wings that form a dihedral angle, especially when the angle between the upper sides is less than 180°.
3. (not-comparable)Of wing pairs, inclined at an upward angle to each other.