Passing through the dead town of Schellbourne last month, I asked one of the few lingering inhabitants why the town was built.

In the sentence you provided, the word "lingering" refers to the inhabitants who are still present in the town, suggesting that they remain there despite the town's desolation and possibly against better judgment or circumstance. It implies a sense of permanence or holding on to the past.

Two synonyms for "lingering" include:

1. Staying
2. Remaining

Other possible synonyms could be: 3. Persistent 4. Residing