Lewis & Short

sponso, āre, v. a. [sponsus], to betroth, affiance, espouse (post-class.).

  1. I. Lit.: aliquam, Dig. 23, 2, 38; Tert. Vel. Virg. 11.
  2. II. Trop.: animam, Paul. Nol. Carm. 18, 43: et sponsabo te mihi in sempiternum, Vulg. Osee, 2, 19; 2, 20.