wisenheimer

 
Pronunciation: /ˈwʌɪz(ə)nˌhʌɪmə/

noun

US informal
  • a person who behaves in an irritatingly smug or arrogant fashion, typically by making clever remarks and displaying their knowledge.

Origin:

early 20th century: from wise1 + the suffix -(n)heimer found in surnames such as Oppenheimer