Do you know ghouls from goblins and ghosts?
early 15c., "apply hot liquids," from Old French fomenter (13c.) "apply hot compress (to a wound)," from Late Latin fomentare, from Latin fomentum "warm application, poultice," contraction of *fovimentum, from fovere "to warm; cherish, encourage" (see fever). Extended sense of "stimulate, instigate" (1620s) was in the French. Related: Fomented; fomenting.