[ME. pollax, polax, Sc. powax = MDu. polaex, pollaex, MLG. and LG. polexe, pollexe (whence MSw. 15th c. polyxe, pulyxe, MDa. polöxe), f. pol, POLL n.1, Sc. pow, MDu., MLG. polle, pol head + AXE: cf. MDu. polhamer = poll-hammer, also a weapon of war. It does not appear whether the combination denoted an axe with a special kind of head, or one for cutting off or splitting the head of an enemy. In the 16th c. the word began to be written by some pole-axe (which after 1625 became the usual spelling), as if an axe upon a pole or long handle. This may have been connected with the rise of sense 2. Similarly, mod.Sw. pålyxa and Westphalian dial. pålexe have their first element = pole. Sense 3 may be a substitute for the earlier bole-axe, which was applied to a butcher's axe.]
^Wise, Terence; Embleton, G.A. The Wars of the Roses. Men at Arms 145. Osprey. 1983: 33. ISBN 0-85045-520-0.
^For instance, Partridge gives the following etymology:
L Palus, stake becomes OE pal, whence ME pol, pole, E Pole, the ME cpd pollax, polax becomes poleaxe, AE poleaxe: cf AX (E)