The word "滋润" is formed by combining two characters, both containing the water radical (氵), which semantically indicates moisture or liquid. "滋" incorporates the water radical with "兹", contributing to meanings like growth or enrichment, while "润" combines the water radical with "闰", suggesting smoothness or lubrication. Together, these characters reinforce the concept of moistening or nourishing, creating a compound word that directly denotes the action or state of providing moisture.