The phrase "element water" refers to the natural substance of water, which is one of the four basic elements believed to make up the universe according to ancient philosophies. Full definition
Humans would never last in the ice - cold waters these creatures call home, but they have special adaptations to battle the elements (scientificamerican.com)
My Vapur Element Water Bottle, click the pic above if you want to see the awesomeness yourself! (cupcakendreams.com)
If element water has 3 stars then it means the monster is weak against Water element. (gamepur.com)