(Anglo-Saxon, el-boga, el = an ell, boga = a bow.)
A knight of the elbow.
A gambler. At one's elbow.
Close at hand. To elbow one's way in.
To push one's way through a crowd; to get a place by hook or crook. To elbow out, to be elbowed out.
To supersede; to be ousted by a rival.
Up to one's elbow
[in work]. Very busy, or full of work. Work piled up to one's elbows.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894