Conflict

an open clash between two opposing groups (or individuals)

opposition between two simultaneous but incompatible feelings

a hostile meeting of opposing military forces in the course of a war

a state of opposition between persons or ideas or interests

an incompatibility of dates or events

opposition in a work of drama or fiction between characters or forces (especially an opposition that motivates the development of the plot)

a disagreement or argument about something important

be in conflict

go against, as of rules and laws