What is a antonym for waggish?

Here are some antonyms for "waggish," depending on the specific nuance you want to convey:

General Antonyms:

* Serious

* Solemn

* Grave

* Earnest

* Dour

* Humorless

* Stoic

Antonyms emphasizing lack of humor:

* Dull

* Boring

* Tedious

* Unfunny

* Lacking in wit

Antonyms emphasizing seriousness:

* Formal

* Professional

* Straitlaced

* Conservative

The best antonym will depend on the context in which you are using the word "waggish."