A Hermit

1. A religious recluse; someone who lives alone for religious reasons; an eremite.
2. A recluse; someone who lives alone and shuns human companionship.
3. A spiced cookie made with molasses, raisins, and nuts.
4. A hermit crab.
5. A hummingbird in the subfamily Phaethornithinae.

In the sense of hermit:

anchorite

eremite

recluse