* Indulge: This is the most common antonym, meaning to give in to a desire or to enjoy something fully.
* Partake: This implies taking part in something, especially eating or drinking.
* Consume: This refers to eating or drinking something completely.
* Engage: This can be used when abstaining from something like a conversation or activity.
* Yield: This implies giving in to a temptation or pressure.
Example:
* Abstain: "I will abstain from alcohol tonight."
* Indulge: "After a long day, I plan to indulge in a hot bath and a good book."
The best antonym will depend on the specific situation and what the person is abstaining from.