Maeght,
Which has nothing to do with a definition of God does it?
Could you explain why this is incoherent and what you mean.
It has everything to do with "the definition of God" (or more accurately, with the absence of one).
"God" is incoherent because it's not defined in any way. You may as well say "pixies", or for that matter "u97869786jh". It's just white noise, information free static. If you want to use "God" as the answer to something then you need
first to explain what you mean by it. That's what
ignosticism entails - essentially, "I have no idea what you mean by "God" and nor have you, so there's nothing to discuss until you do".
In practice though most of the discussions here play a sort of unspoken game in that they assume that the term has been defined and then consider the (always bad) arguments for it as if it had.