friction
n//ˈfɹɪkʃən̩//friktion
The rubbing of one object or surface against another.
(physics) A force that resists the relative motion or tendency to such motion of two bodies in contact.
(figuratively) Conflict, as between persons having dissimilar ideas or interests; clash.
(China, historical) (Second Sino-Japanese War) Conflict, as between the Communists and non-Hanjian Kuomintang forces.