verb: (obsolete, transitive) Decide; determine (a matter disputed or doubtful).
verb: (transitive) Decree by judicial sentence. Now a technical term of Scottish judicature; the use of the word decerns being necessary to constitute a decree.
verb: (obsolete, transitive) Distinguish or separate by their differences (things that differ, one thing from another).
verb: See distinctly (with the eyes or the mind); distinguish (an object or fact); discern.