riprap
RIP-rap
A layer of loose stone used to protect against erosion — placed along riverbanks, shorelines, or embankments. In ice terminology, the rubble of broken ice piled up by pressure. In both cases, the word sounds like what it is: rock thrown down hard.
Etymology
English: possibly reduplication of rap (to strike). Or from rip + rap, suggesting the sound of stones being dumped.
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