GAULT CLAY Meaning of GAULT CLAY in English [ gɔ:lt ]■ noun Geology a series of Cretaceous clays and marls forming strata in southern England.OriginC16: possibly related to Old Swed. galt , neut. of galder 'barren'. Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004