**Di*he"dral** (?), a. [Gr. *di-* = *di`s-* twice + &?; a seat, bottom, base, fr. &?; to sit. Cf. Diedral.]

Having two plane faces; as, the *dihedral* summit of a crystal.

**Dihedral angle**, the angular space contained between planes which intersect. It is measured by the angle made by any two lines at right angles to the two planes.

© Webster 1913

**Di*he"dral** (?), a.

**1.**

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°.

**2.** (Aëronautics)

Of wing pairs, inclined at an upward angle to each other.

© Webster 1913