招摇撞骗

招搖撞騙
zhāoyáozhuàngpiàn
(idiom) to dupe people by passing oneself off as a well-connected individual or a figure of authority

CEDICT

to pass oneself off as someone prominent and deceive people; to swagger and swindle

Wiktionary

借名炫耀，到处诈骗。

重編國語辭典

假借某种名义，到处冒名炫耀，进行诈骗

維基詞典

Entry Composition

1 招摇 zhāoyáo
  1. to rock back and forth
  2. (fig.) to act ostentatiously
  3. to brag
  4. to show off
2 撞骗 zhuàngpiàn to swindle