Alternatively, the word may also be considered a form of saker, rather than a borrowing from Middle English.
v.a.
1to shake, move vigorously:
(
a.1399; MS: a.1399
)
il prist le roy par la mayne dimy genolaunt et schaka sa brace =both arms durement e fortement, disant a luy: ‘Frer, soiez de bone comforte et lee [...]’
147.6
schaker (a.1399)