I am at the CiRCE national conference at the moment and have heard a good on the matter of worlds over the last two days. What follows is nothing more than a brief catalogue of ways in which worlds are spoken of.
“This world”: The word as existential reality; everything this side of the Resurrection and return of Christ; icon of ephemerality.
“The world”: That thing which is contrary to God and attempts to exclude God; “I have overcome the world”
“The real world”: A particular plane of reality; see also “the adult world” or “the teenage world”