General Antonyms:
* Dull
* Boring
* Quiet
* Still
* Inactive
* Stagnant
* Monotonous
* Sleepy
Specific Antonyms:
* Depressed (if referring to mood)
* Slow (if referring to pace)
* Bland (if referring to taste or atmosphere)
* Uninteresting (if referring to engagement)
For example:
* Lively party: Dull party
* Lively discussion: Quiet discussion
* Lively color: Bland color
* Lively child: Quiet child
Choose the antonym that best fits the specific situation.