The phrase "drain water" means to remove or let out the water from a container or a place.
Sentences with «drain water»
Then after a few hours or however long you have you just drain the water from between the two plates. (connoisseurusveg.com)
• To prevent water damage from the inside of your home, you should turn off your water coming into the house and then drain the water in the lines. (rogersinsurance.ca)
Also, don't drain the water out of the tuna, just mix it in and that helps with not being dry. (gymjunkies.com)