equivalent to morning wood, but infinitely more manly and more girthy sounding.
"Man, this morning lumber is no joke. That's the second pair of Levi's I've torn through this week!"
I had such fat morning wood, it would take a lumberjack to cut that shit down.
Liz's most noticeable feature as she woke up was her morning breath. For Mark though, it was definitely his morning lumber. It nearly bruised her ribs as he rolled over.