Antonyms for the phrase "keep reserve" would be words and phrases that imply revealing all or giving away everything without holding anything back. These would include terms like "open book," "share freely," "wear heart on sleeve," "give all," "go all in," "share openly," and "bare it all." Essentially, antonyms for "keep reserve" describe a state of being open and transparent, without any secrets or hidden motives. These concepts could be applied to personal relationships, business dealings, politics, or any other situation in which honesty and openness are valued.