† ˈjettoObs. [ad.It.getto (d'acqua) jet of water.] A jet d'eau. 1644Evelyn Diary 22 Oct., The garden has..fountaines, especialy one of five jettos.1685Phil.Trans. XV. 1093 Two shells to receive the Water from the Jetto's.1699Evelyn Acetaria Plan, Fountains, Jetto's, Cascades.