Lewis & Short

ăpertĭo, ōnis, f. [aperio], an opening, unfolding (only ante- and post-class.).

      1. a. With gen.: floris, Pall. 1, 6, 4: templi, App. M. 11, p. 266, 22: oris, Vulg. Eccli. 20, 15; ib. Ephes. 6, 19.
      2. b. Absol.: cum periculo introitur recenti apertione, Varr. R. R. 1, 63: apertio, the solemn opening of a temple, Serv. ad Verg. A. 4, 301.