adj moved or worked by pressure or flow of air; as, a pneumatic instrument; a pneumatic engine.
2. pneumatical ·adj fitted to contain air; having cavities filled with air; as, pneumatic cells; pneumatic bones.
3. pneumatical ·adj consisting of, or resembling, air; having the properties of an elastic fluid; gaseous; opposed to dense or solid.
4. pneumatical ·adj of or pertaining to air, or to elastic fluids or their properties; pertaining to pneumatics; as, pneumatic experiments.
5. pneumatical ·add. ·adj adapted for containing compressed air; inflated with air; as, a pneumatic cushion; a pneumatic tire, a tire formed of an annular tube of flexible fabric, as india rubber, suitable for being inflated with air.