from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A layer of stones and rocks laying on the bottom of a sea or lake that provides the base for a pier or breakwater.
from the GNU version of the Collaborative International Dictionary of English
- n. A mass of large stones thrown into water at random to form bases of piers, breakwaters, etc.
from The Century Dictionary and Cyclopedia
- n. A mass of large stones thrown into the water to protect the outer face of a dike or breakwater, or a shore subject to encroachment of the sea.
en- + rock + -ment (Wiktionary)