allotropicityrare.|æˌlɒtrəˈpɪsɪtɪ| [f. allotropic + -ity. Cf.electricity.] Capacity for assuming allotropic forms; allotropic nature. 1853Faraday Lect. v. 231 Sulphur is a simple body; and this circumstance greatly increases our astonishment at its allotropicity.