膠こう泥でいこうでいMeanings1nounmortarTechnical term for a paste-like building material used to bind bricks or stones, similar to モルタル.See also: モルタル古こ代だいの建けん築ちくでは、石いしを積つむのに膠こう泥でいが使つかわれた。In ancient construction, mortar was used to stack stones.