This post was written last night, when I had wished I was already asleep, so let's jump to it: Ratchet is a word Young People were using. It's been used in a few primetime shows (2 Broke Girls, Super Fun Night), and thus might be on its way out of the Young People Lexicon.
The nicest definition for "ratchet" is "Undesirable, coarse woman."
It has been used in a large number of hit hip-hop songs this year. A little history, from New York Magazine will provide further insight:
Ratchet can be traced back to the neighborhood of Cedar Grove in Shreveport, Louisiana. “You talk to working class black people [down there],” says Dr. Brittney Cooper, a co-founder of the Crunk Feminist Collective. “Ratchedness comes out of that. And some of that particularity gets lost when it travels.” The first appearance of ratchet in a published song was in 1999, when Anthony Mandigo released “Do the Ratchet” on his Ratchet Fight in the Ghetto album. “Mandigo introduced me to the word, He got it from his grandmother,” remembers Angela Nichols, who goes by Angie Locc and rapped on the track. In 2004, Earl Williams, a producer known as Phunk Dawg, recorded a new version of the song, featuring the better-known Lil Boosie (currently incarcerated), from Baton Rouge, as well as Mandigo and another Shreveport rapper named Untamed Mayne. This version, and the associated dance, caught on and Mandigo’s Lava House Records began making a name for itself.
In it, the Atlanta brothers pretend to be ratchet women describing their ilk: They carry outdated flip phones, go clubbing while pregnant, and try to punch other women in the face. “Ratchet is basically a lack of home training — being out in public and acting like you don’t have any sense,” Philip Houston told the Cut. “Putting a weave in the microwave just to curl it, that’s ratchet.”Some women have "taken back" the word as a means of ownership. That does not make it OK for an Old Person to use. It's a loaded, unkind word, rooted in socioeconomic disparity. Don't use it.
The word has a nasty connotation. It's only used for vocal, outspoken, Black women. As an insult, it says that women must be demure, "well behaved," and exceedingly "classy;" women that are not ratchet have, apparently, gone to great lengths to earn respect.
Old People respect all types of people, regardless of gender, race, or social class.
Ratchet: The Rap Insult That Became A Compliment, New York (read the whole thing)