If you aretalkingabout aqualityor anactivityand you say that someone doesn'tknowthemeaningof the word, youmeanthey do not have thatqualityor have noexperienceof thatactivity:
（某人对做某事）没有经验，一无所知；（某人）完全缺乏某种素质
Work? He doesn'tknowthemeaningof the word!工作？他对工作根本一无所知。
And theironyof Philtalkingaboutethics. He doesn'tknowthemeaningof the word.菲尔谈论道德规范简直是个讽刺。他本身根本就是一个没有道德的人。