See distinctly (with the eyes or the mind); distinguish (an object or fact); discern.
transferred sense
Decree a person etc. to be or to do something by judicial sentence. (in the phrase “to decern in”, obsolete) To mulct in by decree of court.
Decree by judicial sentence that something be done.
intransitive
with simple object
To perceive things as different, or to perceive their difference itself; to differentiate, distinguish, discriminate.