Meaning:

“萝莉” comes from Lolita, a title protagonist of Vladimirovich Nabokov’s novel. In the novel, a middle-aged professor falls in love with 12-year-old Lolita, and “音” here means “voice.” The name “Lolita” has entered pop culture to describe a sexually precocious girl. Later, the term has a more widely use referring to cute young girls or a fashion style which features mid-list couture dresses adorned with frills, lace, and intricately patterned fabric. Chinese netizens have coined the term to refer to the tender voice of underage women, which is popular on streaming sites.

Example:

A: 你认识小李的姐姐吗？

Nǐ rènshí xiǎolǐ de jiějie ma？

Do you know Xiaoli’s elder sister?

B: 认识，她很漂亮，一开口就是萝莉音，好多男生喜欢。

Rènshí，tā hěn piāoliang，yī kāikǒu jiùshì luólìyīn，hǎoduō nánshēng xǐhuan。

Yes. She’s very pretty, and speaks in a cute little girl’s voice. Many boys fancy her.