To nurse to life or activity; to cherish and promote by excitements; to encourage; to abet; to instigate; used often in a bad sense; as, to foment ill humors
{f} stir up; instigate; stimulate; apply water or a medicated liquid (to part of the body)
If someone or something foments trouble or violent opposition, they cause it to develop. They accused strike leaders of fomenting violence. = incite. foment revolution/trouble/discord etc to cause trouble and make people start fighting each other or opposing the government = stir up (fomentare, from fovere )