bootleg adj. inferior, unappealing, worthless. (source: Double-Tongued Dictionary)
Further reading
Samantha Harvey’s novel Orbital is a sensuous, exhilarating meditation about the strangeness of life on a space station, with its mix of tedious tasks and jaw-dropping views. And: a musician who rode the rails in his youth shares the slang he...
Steve, a singer-songwriter from Rock Springs, Wyoming, shares some slang he picked up while months riding the rails and busking. Spanging refers to panhandling, from asking for “spare change.” The term bull refers to a type of security...
What about bootleg recordings of concerts and jam sessions that are highly prized by fans? Those are considered priceless.
That’s a different, far more common meaning that’s well-covered in dozens of other dictionaries and so is not within the purview of this site.
When my daughter started saying it I thought it sounded stupid because I had never heard it used that way. But then again it’s like saying “bogus” in sort of the same way. Stupid, lame, etc. I’m sick of everything being “ghetto”, most of these kids have never seen a ghetto in their lives.