pneu·ma·tol·o·gy 
(n′mə-tŏlə-jē, ny′-)
(n′mə-tŏlə-jē, ny′-)n.
1. The doctrine or study of spiritual beings and phenomena, especially the belief in spirits intervening between humans and God.
2. The Christian doctrine of the Holy Ghost.
pneu′ma·to·logic (-tə-lŏjĭk), pneu′ma·to·logi·cal (-ĭ-kəl) adj.
pneu′ma·tolo·gist n.