Ontic referent – 1.) ontic: of, relating to, or having real being 2.) referent: one that refers or is referred to; especially : the thing that a symbol (as a word or sign) stands for (reference for both terms: http://www.merriam-webster.com)
With regard to morality and ethics, these terms are used in tandem to point to a reference point (standard) by with we determine what is right or wrong. In the case of Monotheism, the ontic referent is God. Without God (transcendent signifier; arbiter) there is only the subjective, metric of mankind.
Ontological Argument – The argument that God, being defined as most great or perfect, must exist, since a God who exists is greater than a God who does not. Compare with argument from design, cosmological argument, and teleological argument. (source link) See: 1.) Alvin Platinga’s Modal Ontological Argument 2.) Anselm: Ontological Argument for God’s Existence 3.)Understanding the Ontological Argument