Lewis & Short

prae-tĕnŭis, e, adj.

  1. I. Very thin or slender (post-Aug.): folium pinūs, Plin. 16, 10, 16, § 38: fila, id. 16, 31, 56, § 128; 19, 6, 34, § 116: bracteae, id. 33, 6, 32, § 100: pons, very narrow, id. 8, 50, 76, § 201.
  2. * II. Of sound, very thin or shrill, Quint. 11, 3, 41.