Two Part Word -- This refers to a Male's Beast (Lut) and the Hairy ball sack (Bag)
This is generally used to describe someone who's incapable of being intelligent or cool on any level. In other words this person is a complete asshole!!
Adam: i don't think this is correct answer
jack: you suck at math lol
Adam: wow! i was writing and publishing my research articles when you were in your dad's lumbar, kiddo
a person whom arches thier back to make thier butt look big. while in the process, thier back gets used to being in that postion and that my friend is lumbar lordosis