One definition of modesty is the behavior, manner, or appearance intended to avoid impropriety or indecency.
plural noun: modesties
“modesty forbade her to undress in front of so many people”
synonyms: unpretentiousness, simplicity, plainness
What are examples of modesty? Well in the 50s, girls had the finger length test in school. The girls had to put their arms down their sides and if their skirt or dress was shorter than their fingertips they had to go home. That may or may not have been extreme. It depends on who you ask.
There are plenty of women walking around with skirts or dresses shorter then that but they wear leggings underneath as if it would make it more modest. Some women even wear leggings to wear with tips alone! As if the leggings were pants. It is incredibly unflattering and immodest (I will not show an example to spare you).
Modesty is not hiding your beauty but saving it.