* Silence: If "repartee" refers to witty conversation, silence would be the complete opposite.
* Monotony: This captures the lack of liveliness and quick wit associated with repartee.
* Dullness: Similar to monotony, this suggests a lack of spark and engagement.
* Seriousness: While repartee can be playful, it can also be clever and insightful. Seriousness implies a lack of this lightheartedness.
* Lack of communication: If "repartee" refers to the back-and-forth of conversation, this would be the opposite.
* Argument: While repartee can be argumentative, it is typically done in a humorous and witty way. A serious argument would be the opposite.
The best antonym will depend on the specific situation and what aspect of "repartee" you want to contrast.