dihedral

plural dihedrals

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

1. not comparablemathematicsConsisting of, relating to or contained between two plane surfaces.

   dihedral angle

2. not comparableHaving wings that form a dihedral angle, especially when the angle between the upper sides is less than 180°.
3. not comparableaeronauticsOf wing pairs, inclined at an upward angle to each other.