Which term refers to someone who is humbly entreating?

The term that refers to someone who is humbly entreating is "suppliant." This word originates from the Latin term "suppliere," meaning "to kneel." A suppliant is often characterized by their earnest and respectful appeal to someone in power or authority, typically in a desperate situation where they seek assistance, mercy, or a favor. The notion of humility is central to this word, as a suppliant approaches their interlocutor with a tone of submission and reverence.

In contrast, the other terms do not carry the connotation of humble entreaty. A "tyro" refers to a beginner or novice, particularly in a specific field or activity, and does not imply any act of seeking favor or assistance. "Supercilious" describes a person who behaves or looks as though they think they are superior to others, which is the opposite of humble entreaty. Lastly, "turpitude" denotes moral corruption or depravity, not related to the act of seeking help or support in a deferential manner.