(1) Save: except. (2) Yonder: distant; remote. (3) Ivy-mantled: cloaked, dressed, or adorned with ivy. (4) Moping: gloomy; grumbling. (5) Of such: of anything or anybody. (6) Bow'r: bower, an enclosure surrounded by plant growth—in this case, ivy. (7) Molest her ancient solitary reign: bother the owl while it keeps watch over the churchyard and countryside. (8) Her ancient solitary rein: metaphor comparing the owl to a queen.