wisenheimer
/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.The wisenheimers who paid no respects to such dolts did not get us into this mess - straight-faced true believers of all stripes did....
- It was always tempting to try and prove that one was enough of a wisenheimer oneself to appreciate anything they could dish out.
Origin
Early 20th century: from wise1 + the suffix -(n)heimer found in surnames such as Oppenheimer.