substratum /.SAb'stratam US: -'streit-; SAb'stre-tsm/ n (pl -ta) /-ts; -ta/ 1 level lying below another: 下面的一層; 下層： a ~ of rock. 下層巖石。 2 foundation: 基礎(chǔ); 根基： The story has a ~ 時(shí) truth, is based upon facts (though perhaps at first, sight seeming false). 這故事有事實(shí)為根據(jù)(雖然乍看或似荒誕不經(jīng))。