I haven't heard it for a long time. I suspect it's still used when talking to children, but it has a patronizing quality which would make most people reluctant to use it with adults.
There's a famous Louis Armstrong song called Lazybones. Thinking of it makes me wonder if the word was common in the language of black people working in the cotton fields.
Yes, I think it is still used, but in restricted settings as Mr T and Mr G have noted. I can imagine saying that to my lazy children, or a teacher chiding some children playfully. I don't think it needs to be patronising.
I use it! I see no need to restrict it to just talking to children, either. I have no trouble calling a coworker or a friend "lazybones" if the situation calls for it. Obviously, I use it in a playful manner, but I've never thought of it as sounding patronizing. 👁 Eek! :eek: