You've likely heard it in two connotations:
One being the western emphasis on sexualized kids, derived from a book from 1955. I won't go into the details. It's triggering and gross. Wikipedia it if you want. 🤮
The second meaning is derived from Japanese fashion culture. The term Lolita fashion is used to define cuteness and innocence with Victorian era and Edwardian era inspired clothing.
angelicpretty.com/en/
I call out that brand because I'm familiar with it. There's a San Francisco store 🤣 though it was started in Japan many decades ago.