Step-by-step explanation:
The definitions for monody are (paraphrased):
A song sung by one actor in a Greek tragedy
A poem mourning one's death
Poe's "The Bells" symbolizes the four stages of life through bell tolls. The four stages are: childhood, youth, maturity, and death.
The definition of "monody" most likely means a poem mourning one's death in Poe's "The Bells". The final stanza refers to the bells tolling as if someone was dying; "throbbing of the bells...sobbing of the bells...moaning and groaning of the bells", this sounds much like someone in their last minutes before death comes to claim them.