Sentence:  Alcohol was poured onto one end of the <WSD>luge</WSD> and as the alcohol traveled down the narrow grooves in the block of ice, it was cooled and then ran directly into the mouth of the waiting drinker on the other end. 
Meaning of the word marked with <WSD> tags:  A piece of ice, bone or other material with a channel down which a (usually alcoholic) drink can be poured into someone's mouth.