Meaning of riprap

rip•rap

Pronunciation: (rip'rap"), [key]
— n., v., -rapped, -rap•ping.
—n.
  1. a quantity of broken stone for foundations, revetments of embankments, etc.
  2. a foundation or wall of stones thrown together irregularly.
—v.t.
  1. to construct with or strengthen by stones, either loose or fastened with mortar.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.