An obviously underage girl who dresses like a whore...

A Bloomer is someone with a bright outlook on life who is optimistic in nature. Bloomer's frolic in every opportunity to be happy and try to make the most out of life. The opposite of a Bloomer is a Doomer. The term Bloomer originated specifically as a counter to the Doomer on sites especially like 4Chan.

A young girl with too much makeup and not enough clothes.

A girl under the age of 15 who dresses look a whore or with prostitute tendencies.

Young girls who dress like prostitutes.

An underage girl who dresses like a prostitute.

A young girl, usually between 10-14 and commonly 12 or 13, who dresses in revealing clothing. Prostitots are usually young girls who want to be seen as sexy and mature by the older men around them, and therefore end up wearing far too much makeup and dressing in what they think is sexy but simply looks skanky. They usually look like mini prostitutes, which is how the name came about. Prostitots may or may not be interested in sex; some are, and others are simply mistaken about what makes them look grown up and glamorous.

Can also be used as a random, nonsensical insult, though this usage is uncommon.