COUMARIN Meaning of COUMARIN in English [ 'ku:mərɪn ]■ noun Chemistry a vanilla-scented organic compound found in many plants.OriginC19: from Fr. ~e , from coumarou , via Port. and Sp. from Tupi cumarú 'tonka bean'. Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004