from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A detailed imaginary world, especially one created by a child.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a prolonged fantasy world invented by children; can have a definite geography and language and history
From Ancient Greek παρά (para, "beside, alongside") + κόσμος (kosmos, "world, universe"). (Wiktionary)