Final answer:
The word 'fallen' in the provided context best matches the meaning of 'decreased in status or importance,' which refers to a decline from a previous, higher condition.
Step-by-step explanation:
The definition of fallen as it is used in line 21 most closely matches the meaning: decreased in status or importance, given the context provided in the excerpt. In a literary sense, fallen often refers to loss or decline, especially in terms of social status or power. A key aspect here is the atmosphere of decay and past vibrant life now extinguished, which strongly suggests a decrease from a previous, loftier condition, aligning well with option 3 from the given choices.