The function f(x) assigns higher values to words that are associated with celestial bodies, such as the moon and the sun, as well as words related to nature, such as mountains. It also assigns higher values to words that are associated with positive emotions, like joy. Conversely, it assigns lower values to words that are not strongly associated with these concepts.

Please note that this description is based on the limited experimentation conducted. It would be advisable to perform further tests and gather more data to ensure the accuracy and generalizability of the description.