As I used my stealth to move through the shadows, I thought it ironic that the rich man's expensive and probably imported carpets should assist me in keeping quiet.

ironic 是形容词，来自名词 irony（讽刺）。这个词描述一种矛盾或出乎意料的情况，即事情的结果与预期相反，或表面现象与实质相反。在这里指富人本想炫耀的昂贵地毯，反而帮助了潜入者保持安静这种矛盾现象。