The phrase "most close-lipped" refers to an individual who is extremely secretive, not prone to revealing personal information or opinions. Antonyms for this phrase include "outspoken," "loquacious," "verbose," "talkative," "garrulous," and "chatty." These words describe individuals who are more open and expressive, willing to share their thoughts and feelings with others. Being outspoken, for example, conveys a sense of frankness and honesty, while being loquacious suggests a tendency to talk excessively or in a rambling fashion. Regardless of the specific antonym, these words all describe individuals who are more extroverted and communicative than someone who is "most close-lipped.