1Something that has been added or appended; an added statement, word, etc.; (Grammar) an affix.
2The action or an act of adding or appending something.
Middle English; earliest use found in Statutes of the Realm. From Anglo-Norman adjeccion, adjeccioun, Anglo-Norman and Middle French adjection (French †adjection) something that has been added or appended, act of adding or appending something and its etymon classical Latin adiectiōn-, adiectiō act of adding, addition, anything added, additional clause or proviso from adiect-, past participial stem of adiicere + -iō.