If someone claims that the concept of God is ambiguous and it is meaningless to talk about its existence, then such a person cannot take a stance as far as knowledge is concerned. Wouldn't an Agnostic Ignostic be an absurd proposition? Or is it a valid position given that one may encounter an unambiguous definition of God in the future?
Ignosticism is the idea that the question of the existence of God is meaningless, because the term "god" has no unambiguous definition. Ignosticism requires a good, non-controversial definition of god before arguing on its existence.