A pantheist is a person who holds the religious idea that God and the universe are one thing, and that God is present in all natural things. The idea itself is pantheism; the person is a pantheist. You will meet the word in religion and philosophy more than in daily chat. It can also sit in front of a noun (a pantheist writer), though pantheistic is the more usual adjective for a view, a poem, or a feeling. A pantheist and a theist both talk about God, but they do not picture the same kind of God: one finds God in the world itself, the other as someone apart from it.