Sentence:  There was no time to pick out a penny ; I got a coin between my thumb and forefinger , leaned my <WSD>elbows</WSD> in a very natural and casual manner on top of the truck cab and flipped my little missile . 
Meaning of the word marked with <WSD> tags:  hinge joint between the forearm and upper arm and the corresponding joint in the forelimb of a quadruped