jokeproof
/ˈdʒoʊkpruːf/Definitions
1. adjective
Impossible to understand as a joke, or unable to be tricked by a joke.
“The comedian’s joke was so complex, it seemed jokeproof, but the audience still didn’t get it.”
2. noun
A person or thing that is immune to jokes.
“With his deadpan expression, he was the ultimate jokeproof character in the comedy troupe.”