1820-30;fire + water; probably a translation of an expression in an Algonquian language, as Ojibwaiškote·wa·po· whiskey (earlier, other distilled liquors), equivalent to iškote·w-, combining form of iškote· fire + -a·po· liquid
Examples from the web for firewater
The dining room is casual, the food simple but generous, with wine from nearby and the offer of some firewater after dinner.
Only ultra low sulfur diesel fuel shall be fired in the emergency generator and the firewater pump.
On-road specification diesel will be the only fuel for the emergency generator and firewater pump.
The only source of other pollutants will be an emergency firewater pump that will operate on diesel fuel.
The wastewater can then be used as make-up water for the firewater system as necessary or discharged.
British Dictionary definitions for firewater
firewater
/ˈfaɪəˌwɔːtə/
noun
1.
any strong spirit, esp whisky
Word Origin and History for firewater
n.
"alcoholic liquor," 1826, American English, supposedly from American Indians, from fire (n.) + water (n.).