to instigate or foster (discord, rebellion, etc.); promote the growth or development of: to foment trouble; to foment discontent.
2.
to apply warm water or medicated liquid, ointments, etc., to (the surface of the body).
Origin: 1350–1400; Middle English fomenten < Late Latin fōmentāre, verbal derivative of Latin fōmentum soothing application, poultice, contraction of *fōvimentum, equivalent to fōv(ēre) to keep warm + -i- -i- + -mentum-ment
c.1400 (implied in fomentation), from M.Fr. fomenter, from L.L. fomentare, from L. fomentum "warm application, poultice," from fovere "to warm, cherish, encourage." Extended sense of "stimulate, instigate" (1620s) was in the French. Related: Fomented; fomenting.