agnosticism comes from agnostic (coined by T. H. Huxley in 1869) + -ism; ultimately from Ancient Greek ágnōstos ('unknowable'), from a- ('not') + gnōstós ('known'). Morphologically, the word is transparent: -ism is attached to the older base named in the history, so the modern form packages an inherited or borrowed stem inside a later English derivative. In modern use, the noun sense is "the view that the existence of God is unknown or unknowable", which keeps the etymology connected to the word's present dictionary value rather than treating it as a merely historical label. The wider word family includes related English forms such as agnostic, gnosticism, gnostic, showing how the same base continues to support neighboring English vocabulary. The principal historical forms in the chain include Ancient Greek ágnōstos, Proto-Indo-European *ǵneh₃-, which anchor the explanation in named linguistic material.