insubstantial

adj

Etymology: Probably from Middle French insubstantiel, from Latin insubstantiālis, from in- + substantiālis. By surface analysis, in- + substantial.

1. Lacking substance; not real or strong.

   “The bridge was insubstantial and would not safely carry a car.”

   “By manipulating the flow of magic, Eragon quickly descended from the Ra'zac's lair—which the insubstantial wall of stone once again hid—to the ledge.”