Sentence:  <WSD>"Terra sigillata</WSD>" (sealed earth) was a greasy clay, containing silica, alumina, chalk, magnesia and oxide of iron, found on the Greek islands of Lemnos, Melos and Samos. 
Meaning of the word marked with <WSD> tags:  A type of astringent earth or clay originally from the Greek islands, formerly used as a medicine and antidote.