Basically, it's "Life" with a "d" at the end. I suppose you could consider it to be an Adverb of "Life". Of course it's not really an Adverb, but it's sort of like how Google eventually turned into "Google it." I could maybe see how life insurance companies might want such a domain, which is the only reason I can see why it might be priced high. That, and it's only 5 letters long.