Lewis & Short

excelsĭtas, ātis, f. [excelsus], loftiness, height.

  1. I. Lit.: montium, Plin. 2, 64, 64, § 160: harundinis, id. 16, 36, 66, § 167: lilii, id. 21, 5, 11, § 23.
  2. II. Trop.: excelsitas animi et magnitudo, Cic. Off. 3, 5, 24.