rip-rap

noun

civil engineering broken stones loosely deposited in water or on a soft bottom to provide a foundation and protect a riverbed or river banks from scour: used for revetments, embankments, breakwaters, etc

Word Origin for rip-rap

C19: reduplication of rap 1

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Examples from the Web for rip-rap

Historical Examples of rip-rap

Want to rip-rap the outer edge of this water hole, so the bank will not cave in and undo all our work!
The Pony Rider Boys in New Mexico
Frank Gee Patchin
The heavy masonry bulkhead was supported on piles and rip-rap, as shown in Fig. 18.
Transactions of the American Society of Civil Engineers, Vol. LXVIII, Sept. 1910
B. H. M. Hewett
When the shield had traveled 25 ft. through the rip-rap, the piles which support the bulkhead were met.
Transactions of the American Society of Civil Engineers, Vol. LXVIII, Sept. 1910
B. H. M. Hewett

Word Origin and History for rip-rap

also riprap, "loose stone thrown down in water or soft ground as foundation," 1822, American English, perhaps connected with earlier nautical word rip-rap meaning "stretch of rippling water" (often caused by underwater elevations), 1660s, probably of imitative origin (cf. riprap "a sharp blow," 1570s).