"Maul", that is. It's present in the 1913 Websters that Debian includes with its dict package. Dictionary.com has "long heavy hammer" as its primary definition of the noun, with [link|http://www.dictionary.com/search?q=maul&db=*|roots tracing back to Middle English].
An axe is designed for cutting. Thin head. I'll bury an axe in a log real quick if I try to split with it. Mauls, OTOH, have a sharp edge but a fat butt, and cleave wood readily. Far faster than a sledge and wedges, if you know how to work them right, particularly on frozen wood.