procedure TForm1.btn_deleteClick(Sender: TObject);
var wortliste: TStringList;
    sWort: String;
begin
    wortliste := TStringList.Create;
    try
       wortliste.LoadFromFile('Wortliste.txt');
       sWort:=ed_eintragen.Text;
       for i:=0 to wortliste.Items.Count -1 do
       begin
         if wortliste.Items[i] = sWort then
         wortliste.Delete(wortliste.Items[i]);
       end;
       wortliste.SaveToFile('Wortliste.txt');
    finally
      wortliste.Free;
    end;

end;