Guzzle

"Well, you've got a gas guzzler," I told a student, who was in pain over the cost of gasoline.  And he was puzzled.  So I explained--"to guzzle" is to drink greedily, and excessively.

And where does it come from?  "Origin unknown," says thefreedictionary.com.   Probably from Old French gossilier, says the online etymology Dictionary, which traces the word to the 1570s.

So it's a mystery--like the price of gasoline!