Sentence:  There enters into such things a great national sin, a far greater sin than drink—the habit of respecting a gentleman. Snobbishness has, like drink, a kind of grand poetry. And snobbishness has this peculiar and devilish quality of evil, that it is rampant among very kindly people, with open hearts and houses. But it is our great <WSD>English vice</WSD>; to be watched more fiercely than small-pox. If a man wished to hear the worst and wickedest thing in England summed up in casual English words, he would not find it in any foul oaths or ribald quarrelling. He would find it in the fact that the best kind of working man, when he wishes to praise any one, calls him “a gentleman”. It never occurs to him that he might as well call him “a marquis”, or “a privy councillor”—that he is simply naming a rank or class, not a phrase for a good man. 
Meaning of the word marked with <WSD> tags:  Snobbishness; sentimental royalism; idealistic love of class and aristocracy.