definition of seiche
seiche. n. A wave that oscillates in lakes, bays, or gulfs from a few minutes to a few hours as a result of seismic or atmospheric disturbances. [French dialectal, exposed lake bottom, probably from French., feminine of., dry; see sec 1 .]. (seÉªÊ).oun. 1. seiche-a wave on the surface of a lake or landlocked bay; caused by atmospheric or seismic disturbances. undulation, wave - (physics) a movement up and down or back and forth.