riprap
UK[ˈrɪprap]US[ˈrɪpˌræp]
n
A loose assemblage of broken stones or concrete blocks placed together to protect a structure or embankment from erosion by water or ice.
v
To protect or strengthen with riprap.
Etymology
The word 'riprap' is a 19th-century American English reduplication, likely based on the earlier nautical term 'rip-rap', meaning a stretch of rippling water caused by underwater obstructions. The term was then applied to the stones that cause such ripples or are used to armor against them. This process illustrates how a descriptive term for a natural phenomenon (rippling water over rocks) was transferred to name the human-made solution (a protective layer of stones) for controlling erosion along shorelines and riverbanks.
Analysis
This is a reduplicative compound, a word formed by repeating or altering a sound. It is not productively built from distinct, separable morphemes in modern English.
Examples
The engineers used large granite boulders as riprap along the riverbank to prevent further erosion.
The construction plan includes riprapping the slope below the new bridge abutment.
The shoreline was stabilized with a layer of riprap to absorb the energy of the waves.