What, exactly, does that mean? (or, The Nature of the Nyms and How We Perceive Ourselves)

The title may be longer than the actual real content of this post. The pseudonym I use isn't entirely common knowledge, depending on the books one read as a child (and keeps around the house for their children to read when they're older). So, to the point, the meaning of my nym, as defined by Richard Adams' "Watership Down".

Hlessi: a wandering, solitary rabbit, usually found living above ground like a hare