la·cu·bri·ous
Pronunciation: la-'cü-brE-&s also -'cyü-
Function: adjective
Etymology: irregular derived with a positive twist from lackadaisical created in 1994

easy to chill out or hang out with. jason mraz uses it in one of his songs.

Update: Evidently it is a made up word. From an interview with Variety -
“I have a friend who calls himself Dr.Lacubrious,” Mraz said. “He’s like, it means lazy, its another word for lackadaisical. We couldn’t find it anywhere, and one day he left a message on my machine, and he’s like, you won’t find it in the dictionary because I made it up. And I thought it was very appropriate, because it is based on a friend of mine who’s the king of one-liners, who’ll say anything to get what he wants. And he’s usually pretty smooth about it.”