rock-ribbed

or rock-rib

[ rok-ribd ]
/ ˈrɒkˌrɪbd /

adjective

having ribs or ridges of rock: the rock-ribbed coast of Maine.
unyielding; confirmed and uncompromising: a rock-ribbed conservative.

Origin of rock-ribbed

First recorded in 1770–80
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

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