Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† pneumătĭcus, a, um, adj., = πνευματικός, of or belonging to air or to wind, air-, wind-, pneumatic; of machines that are driven by the force of air: Ctesibius, qui pneumaticas res invenit, Vitr. 9, 9: organa, Plin. 19, 4, 20, § 60: ratio, id. 7, 37, 38, § 125.