Megalomaniac
/ˌmɛɡəloʊˈmeɪniæk/
Synonyms
- domineering
- narcissist
- dictatorial
- egomaniac
- power-hungry
Slang Meanings
Power freak
He's a total power freak, always bossing everyone around like a megalomaniac.
Control freak
Don't be such a control freak; you're coming off as a megalomaniac.