Emily Dickinson Lexicon

PNEU-MAT'IC, or PNEU-MAT'IC-AL, a. [numat'ic; Gr. πνευματικος, from πνευμα, breath, spirit; πνεω, to breathe or blow.]

1. Consisting of air, as a thin compressible substance; opposed to dense or solid substances. The pneumatic substance being, in some bodies, the native spirit of the body. – Bacon.
2. Pertaining to air, or to the philosophy of its properties; as, pneumatic experiments; a pneumatic engine. – Locke. Encyc.
3. Moved or played by means of air; as, a pneumatic instrument of music.