Ooooo! Big word! Here's what it means:

on·tol·o·gy

Pronunciation: än-'tä-l&-jE

Function: noun

1 : a branch of metaphysics concerned with the nature and relations of being

2 : a particular theory about the nature of being or the kinds of existents

on·to·log·i·cal

Pronunciation: "än-t&l-'ä-ji-k&l

Function: adjective

1 : of or relating to ontology

2 : relating to or based upon being or existence

ontological argument

Function: noun

: an argument for the existence of God based upon the meaning of the term God

& = the "uh" sound, like the sound an atheist might make if you whacked him in the head with a Bible.

ä = the "ahh" sound, like someone who finally "gets it."