REGOLITH Meaning of REGOLITH in English [ 'rɛg(ə)lɪθ ]■ noun Geology the layer of unconsolidated solid material covering the bedrock of a planet.OriginC19: from Gk rhēgos 'rug, blanket' + -lith . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004