conflict

Go against, as of rules and laws.

“This behavior conflicts with our rules”

Be in conflict.

“The two proposals conflict!”

An open clash between two opposing groups (or individuals).

“the harder the conflict the more glorious the triumph”

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

A disagreement or argument about something important.

“the familiar conflict between Republicans and Democrats”

An incompatibility of dates or events.

“he noticed a conflict in the dates of the two meetings”

A state of opposition between persons or ideas or interests.

“his conflict of interest made him ineligible for the post”

“a conflict of loyalties”

Opposition between two simultaneous but incompatible feelings.

“he was immobilized by conflict and indecision”

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

“this form of conflict is essential to Mann's writing”