I couldn't help but look it up! I can't stand to know that I'm living in ignorance, so I had to! I won't ruin it for others. I was nowhere close, though. I would've guessed something having to do with the wind.
OK time to put you out of your misery Big Supes. ;)
Sassenach is a word used chiefly by the Scots to designate an Englishman.
It derives from the Scottish Gaelic Sasunnach meaning, originally, "Saxon", from the Latin "Saxones"; it was also formerly applied by Highlanders to (non-Gaelic-speaking) Lowlanders.
Today it is usually used in jest, as a (friendly) term of abuse. :D