Noun. From "Homeless showboat", an overly eager, attention seeking street individual with no discernible place of residence. Often known to play instruments/sing, juggle poorly, and engage in intentionally shocking acts for money and/or attention. While very popular in urban areas by visiting midwestern tourists, often vilified by locals and less ambitious members of the homeless community.
"Did you see that bum? He was trying to eat like, 14 bottlecaps? Fucking Hoboat."
Noun. Stemming from "homeless heartthrob", a member of the homeless community that possesses many of the physical attributes valued and sought by the superficial man; i.e., come-hither eyes, succulent lips, a sexy smile, flowing hair, shapely figure, etc. Rarely witnessed and once thought to be extinct in North America, the homethrob resides at the top of the homeless food chain.
"Hey, did you just see that guy crawling out of the dumpster? If you took the diaper off of his head, wiped the piss off of his pants, sprayed him with a firehose and had the "I am God" tattoo laser-removed from his forehead, I swear he would be a spittin' image of George Clooney. Talk about a homethrob!"