rainwaterEtymologyFrom Middle English reinwater, from Old English reġnwæter, equivalent to rain + water. Cognate with West Frisian reinwetter, Dutch regenwater, German Regenwasser, Swedish regnvatten.rainwater means A surname. Lexicurio rates it Rare gem — a strength score of 79 out of 100.nameA surname.nounRainfall.“In early December, as rainwaters had started the monthlong process of flooding mines and washing out rail lines, workers lined up before 1 p.m. at an easy-to-miss storefront depot in Mackay.”Water (for a house, etc.) sourced from rain which has not joined a spring, stream or river, pond, lake or sea.“Constructed of hard flint stone, which came as ballast from England and is now painted coral white, the house has a fishpond, or catchment, roof, dating from 1788, to collect rainwater.”