The Merriam-Webster English Dictionary defines "opening your article with a quote from a dictionary" as "the most bush-league garbage move of all time"—but that's because it's mainly used by pimply baby boys in red states who want you to know how personally wounded they are by the existence of Black History Month. In some cases, consulting a dictionary can be legit instructive. Like right now, when we have young women running around proselytizing about "modesty" in the name of women's lib. Um, ladies, no.
Let's consult the dic.
1530s, "freedom from exaggeration, self-control," from M.Fr. modestie or directly from L. modestia "moderation, sense of honor, correctness of conduct," from modestus "moderate, keeping measure, sober, gentle, temperate," from modus "measure, manner" (see mode (n.1)). Meaning "quality of having a moderate opinion of oneself" is from 1550s; that of "womanly propriety" is from 1560s.
This is what "modesty" means. The key points here are "correctness of conduct" and "womanly propriety." If we're looking at the concept of modesty in the non-humble sense, it is a gendered term. It means adhering to a paternalistic and historically oppressive moral code. It means "know your place." It means that certain behaviors are "appropriate" for a woman and others aren't—not for a human being (we're not talking about murder or dog-marriage here), but for a woman. It means that ladies need to be covering up their tittayz.
Ladies. You do not need to be covering up your tittayz.
Now, that doesn't mean that you need to be showing them off and waggling them about in church, or splitting the difference by sort of intermittently flashing them like a strobe light. It just means that you get to do whatever you want with them, regardless of any and all 400-year-old notions about "womanly propriety." Barring public nudity laws (which are also kind of silly, but whatevs), the idea that society can tell you how much of your body to reveal or hide implies that your body does not belong to you. The concept of modesty is proprietary and patriarchal and ancient. I'm pretty sure that even the most hardline anti-feminist can admit who owned women's bodies in the 1560s, when the term came plopping out of the etymological birth canal. Hint: it wasn't women.