JANKY

Recently, in conversation, a friend, who is a "millennial", said, "That's really janky!"

"That's a new word for me;  is it slang?", I asked.

"I don't think so;  I've used it for a long time."

Oxford Dictionary:  janky:  of extremely poor or unreliable quality.  Informal.  Unknown origin. First usage from the 1990s.

The Urban Dictionary:  janky:  inferior quality;  held in low social regard;  old and dilapidated; refers almost exclusively to inanimate objects, not to people.