| a. | 1. | Having two plane faces; as, the dihedral summit of a crystal. | |||
| 2. | Of a kite or an aëroplane, having wings that make with one another a dihedral angle, esp. when the angle between the upper sides is less than 180°. | ||||
| 3. | (Aëronautics) Of wing pairs, inclined at an upward angle to each other.
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