Source : Webster's Revised Unabridged Dictionary (1913)

Perdurable \Per*dur"a*ble\, n. [Cf. F. perdurable, OE.
   pardurable. See {Perdure}.]
   Very durable; lasting; continuing long. [Archaic] --Chaucer.
   Shak. -- {Per*dur"a*bly}, adv. [Archaic]

Source : WordNet®

perdurable
     adj : very long lasting; "less durable rocks were gradually worn
           away to form valleys"; "the perdurable granite of the
           ancient Appalachian spine of the continent" [syn: {durable},
            {indestructible}, {undestroyable}]