🔼The name Vashti in the Bible
Vashti is the only woman in the Bible whose name starts with a V. That's no real miracle because the Hebrew language doesn't have a V. In later Hebrew the letter beth began to sound like a v — that's where the names Avraham and Tel Aviv (see the Biblical name Tel-abib) come from — but in the Bible, there are no v's. The only letter that comes close is the letter waw, but only very few words start with a waw. Actually, there are more names in the Bible that start with a waw (5 or 6) than there are words that start with a waw (2 nouns, 1 verb and 1 adjective). But the waw is also a demonstrative particle, meaning "and," and that makes it one of the most occurring letters in the Bible.
Vashti is the queen of Persia, wife of king Ahasuerus. One day both the king and the queen host banquets, each in their own quarters. When the king gets tipsy he wants to show off Vashti's beauty, but Vashti decides she has better things to do and doesn't show. This upsets the king but also his court because all the men begin to fear that Vashti's refusal will lead the women of the realm to rampant uppitiness. Vashti is subsequently stripped of her royalty, and the hunt for a replacement commences. Scores of pretty young women are rounded up and brought to Susa for the king to make a selection. He chooses Hadassah, a beautiful exile, who is being raised by Mordecai, whose grandfather was the brother of king Saul, both sons of Kish. Hadassah, now named Esther, is the daughter of Abihail, the brother of Mordecai's father Jair.
Esther famously averts the holocaust architected by Haman — a feat still celebrated in the feast of Purim. Had queen Vashti been more compliant, that holocaust may have occurred.
🔼Etymology and meaning of the name Vashti
The name Vashti is not a Hebrew name but a Persian one. Jones' Dictionary of Old Testament Proper Names reports close relations with an Arabic feminine noun (or name) that means Beautiful One, and thus Jones translates this name with Beautiful Woman (as does NOBSE Study Bible Name List).
But there are a few ways to transliterate a name from Persian to Hebrew, and the way this name was Hebraized may indicate a bit of a word joke.
As noted above, the letter waw most often occurs as a junction between words, but it's always stuck inseparably to the beginning of the second word, and sometimes it occurs at the beginning of a sentence, tying this sentence to the previous one. It mostly simply means "and," but often it's used to "introduce a circumstantial clause" (as HAW Theological Wordbook of the Old Testament eloquently puts it), as in "why is your countenance sad since/when you are not sick? (Nehemiah 2:2).
When we treat the waw of the name Vashti as the waw-particle, and drop it all together, what remains is the word שתי (sheti), meaning a drinking, from the verb שתה (shata I), meaning to drink:
This noun שתי (sheti is used in the Bible only once, in Ecclesiastes 10:17: "Blessed are you, O land, whose king is of nobility and whose princes eat at the appropriate time — for strength and not for drunkenness" (NAS).
But the curiousness of all this is that even the Masoretic symbols of the word שתי and the name ושתי are identical.
To a Hebrew audience, the name Vashti may have sounded like When Drinking (=that's what you get!).