Discernment is based on the Latin word "discernere" which is based on the root word "cern".
"dis" means away from,
cern means “to separate with a sieve” (the noun), or “to sift” (the verb).
As a tool, the sieve is used to refine something that is already fine, like refining powdered sugar by sifting it through a sieve.
So discernment is a state of being that we use like a tool to refine and separate out the finer parts of what we want.