I / invŏlūtĭo
noun

invŏlūtĭo

gen. invŏlūtōnis · gender feminine · decl. 3rd
a rolling up; gathering of itself together; that which is inwrapped
a rolling up, gathering of itself together: corporis spirae similis sive canina involutio, Cael. Aur. Acut. 3, 11, 103; concr., that which is inwrapped or infolded, Vitr. 10, 11.