Lewis & Short

spissāmentum, i, n. [spisso], that which is used to compress or stop up any thing, a stopple, plug (post-Aug.): firmiori (quam cera) spissamento opus est, Sen. Ep. 31, 1: spissamento facto de harundinum foliis, Col. 12, 49, 4: faeniculi, id. 12, 49, 4, § 6; 12, 7, 3; 12, 9, 2.