Lewis & Short

fontānus, a, um, adj. [fons], of or from a spring or fountain, spring-.

  1. I. Adj.: aqua, Cels. 2, 18; Col. 12, 9, 2: ora, Ov. F. 1, 269.
  2. II. Subst., in late Lat.: fontāna, ae, f., a spring, fountain, Innocent. de Cas. p. 245 Goes.