from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The doctrine or study of spiritual beings and phenomena, especially the belief in spirits intervening between humans and God.
- n. The Christian doctrine of the Holy Ghost.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The study of spiritual beings and phenomena, especially the interactions between humans and God.
- n. The study of the Holy Spirit as revealed in Scripture.
from the GNU version of the Collaborative International Dictionary of English
- n. The doctrine of, or a treatise on, air and other elastic fluids. See pneumatics, 1.
- n. The science of spiritual being or phenomena of any description.
from The Century Dictionary and Cyclopedia
- n. The doctrine of or a treatise on the properties of elastic fluids; pneumatics.
- n. The branch of philosophy which treats of the nature and operations of mind or spirit, or a treatise on it.
- n. The study of the beliefs, practices, and organizations of men with reference to a supposed world of spirits; spiritual philosophy.
- n. In theology, the doctrine of the Holy Spirit.
Ancient Greek πνεῦμα (pneuma), "breath", and -logy. (Wiktionary)