Pike Axe

[RBasler]

OK, here's a question that has been bugging me for years: Exactly what is a "Pike axe"? I've checked the references in my library (including G.C Stone), I've exercised my Google-Fu, but I am coming up with a blank (well, not exactly blank: Google redirects to "Halberd.) Pikes were pikes, and when you've got something that long and skinny, adding extra weight at the tip for something like an axe blade is generally a bad idea.
There was the "Pole Axe", which was generally a longer, more axe-like halberd-ish weapon, The "Pick Axe", which is a tool, and the rather handy "Poll Axe", which was a shorter (~6" overall) halberd-ish weapon with a pronounced top spike and often had a broad hammer-head opposite the axe blade, and was usually used for armored single combat. CQB the the tin-can crowd.
What did Steve Jackson have in mind when he wrote "Pike Axe"?