tight-ass

noun

ˈtīt-ˌas 

chiefly US slang

: a rigidly straitlaced, conventional, or inhibited person

As Indiana warmed up, Wilkerson noticed Bo Ellis, Marquette's star forward, pointing to the Hoosiers' retro warmups and laughing. Clearly, this game matched the cool dudes from Milwaukee against the tight-asses from Bloomington.

—Jack McCallum

tight-assed

ˈtīt-ˌast 

adjective

Like the schoolteachers who had tormented their childhoods, earnest and tight-assed, humorless and self-righteous.

—Robert Stone

Word History

First Known Use

1971, in the meaning defined above