Definition of: dirigible

(dir′ə·jə·bəl) adjective
1. That may be directed or controlled: a dirigible balloon.
2. Aeron. Designating an airship, the outer envelope of which is of elongated form, provided with a propelling system, cars, rudders, and stabilizing surfaces. The form of the envelope may be nonrigid, by the pressure of the contained gases assisted by the car–suspension system; rigid, by a framework contained within the envelope; or semirigid, by means of attachment to an exterior girder construction containing the cars.
—noun An air-ship. [<L dirigere DIRECT + -IBLE]
—dir′i·gi· bil′i·ty noun
A RIGID TYPE OF DIRIGIBLE