Which word best describes a person who acts without restraint to morals or conventions?

The word "libertine" best describes a person who acts without restraint to morals or conventions. A libertine is someone who leads a life of self-indulgence and lacks regard for societal norms, particularly in matters of ethics, morality, or sexual conduct. This term often carries connotations of debauchery and hedonism, highlighting a rebellious disregard for established moral standards.

In contrast, the other choices do not convey the same meaning. "Lambaste" refers to harshly criticizing or berating someone, which is unrelated to a person's behavior regarding morals or conventions. "Lachrymose" describes someone who is tearful or prone to weeping, reflecting emotional sensitivity rather than a lack of moral restraint. "Limpid" refers to something that is clear or transparent, often used to describe water or writing, and does not relate to behavior or morality at all. Thus, the term "libertine" accurately encapsulates the essence of acting without moral or conventional limits.