riprap

Apparently a reduplication (with vowel dissimilation) of rap (“blow, stroke”).

• (UK) IPA^(key): /ˈɹɪpɹap/

riprap (countable and uncountable, plural ripraps)

1. An underwater bank seen as a danger to shipping.
   • 1982, TC Boyle, Water Music, Penguin 2006, p. 423:

     They hold on, spray flying, the ceaseless racket of water impacting on rock all but swallowing them, the river pitching dizzily, snags and riprap raking like claws at the bottom of the boat.

2. (chiefly Canada, US) Rocks or other materials used to shore up an embankment, deter or prevent erosion, guide shipping, or serve as a temporary mooring.

riprap (third-person singular simple present ripraps, present participle riprapping, simple past and past participle riprapped)

1. To form a riprap in or upon.

From English riprap.

• Hyphenation: rip‧rap

riprap

1. a riprap rocks or other materials used to shore up an embankment, deter or prevent erosion, guide shipping, or serve as a temporary mooring

riprap

1. to riprap