Lewis & Short

nĭvārĭus, a, um, adj. [nix], of or belonging to snow: nivarium colum, a strainer filled with snow, through which generous wines were filtered, whereas the commoner sorts were merely passed through a linen cloth, filled with snow, Mart. 14, 103 in lemm.; Dig. 34, 2, 21; the latter called nivarius saccus, Mart. 14, 104 in lemm.