The term 'Danish Weights' refers to a system of weights and measures used in Denmark from the Middle Ages until the 19th century. The two crossword solutions, SERE and ESER, are both derived from the Old Norse word for weight, sær. SERE is the singular form of the word, while ESER is the plural form. Together, they refer to the system of Danish weights and measures that was used in the country for centuries.