The bone of the arm (humerus) meets both the ulna (the inner bone of the forearm) and radius (the outer bone of the forearm) to form a hinge joint at the elbow. The radius and ulna also meet one another in the elbow to permit a small amount of rotation of the forearm.
The emigres were those who helped to spur on the revolution. People were tired of being poor and watching the royalty get richer without any work.
Expatriate on the other hand, rather than stressing the movement aspect, is centered on the fact of living somewhere else. The main difference between expatriate and immigrant and emigrant is that both immigrant and emigrant imply a sense of permanence, but expatriate does not have the connotation of a permanent move.