Theological noncognitivists claim that the main purported definition for "God", which is "creator of the universe (or multiverse, for those who speak of "other universes") is incoherent because the word "creator" can only be defined in terms of things within the already existing universe (or multiverse) creating other things within the already existing universe.
Theological noncognitivists are those who claim that all other purported definitions of the term "God" are circular. For instance, "God is that which caused everything but God", defines "God" in terms of "God". They also claim that in Anselm's definition "God is that than which nothing greater can be conceived", that the pronoun "which" refers back to "God" rendering it circular as well.
Others who label themselves as theological noncognitivists argue in different ways, depending on what one considers the "theory of meaning" to be. Michael Martin, writing from a verificationist perspective, concludes that religious language is meaningless because it is not verifiable.
George H. Smith uses an attribute-based approach in an attempt to prove that there is no concept for the term "God": he argues that there are no meaningful attributes, only negatively defined or relational attributes, making the term meaningless.
Some theological noncognitivists assert that to be a strong atheist is to give credence to the concept of God because it assumes that there actually is something understandable to not believe in. This can be confusing because of the widespread claim of "belief in God" and the common use of the series of letters G-o-d as if it is already understood that it has some cognitively understandable meaning. From this view strong atheists have made the assumption that the concept of God actually contains an expressible or thinkable proposition. Granted, this depends on the specific definition of God being used, but most theological noncognitivists do not believe that any of the definitions used by modern day theists are coherent.
As with ignosticism, many theological noncognitivists claim to await a coherent definition of the word God (or of any other metaphysical utterance purported to be discussable) before being able to engage in arguments for or against God's existence.