The phrase 헛물켜다 literally translates to “meaninglessly drinking a huge amount of water”, however as it is a slang, there’s always a figurative meaning to it.
This phrase is used mainly when someone makes a pointless amount of effort trying to achieve something that is impossible or unpractical.
For example, if you see someone effortlessly trying to be a K-pop idol when they are not talented enough, you may say 헛물겨다. In English, it is similar to the saying that goes “quit chasing rainbows”.
