Lewis & Short

laeto, āvi, ātum, 1, v. a. [laetus-facio], to make joyful, to delight, cheer, gladden.

  1. I. Lit. (ante- and post-class.): oculos specie laetavisti optabili, Liv. Andron. ap. Non. 132, 32: te ut triplici laetarem bono, Att. ib.: frontem alicujus serena venustate, App. M. 3, p. 134, 16.
  2. II. In partic., of the soil, to fertilize, render fertile, manure (postclass.): in laetandis arboribus, Pall. 1, 6, 18: loca sterilia, id. 1, 6, 13.