conflict
noun
°A clash or disagreement, often violent, between two opposing groups or individuals.
"The conflict between the government and the rebels began three years ago."
°An incompatibility, as of two things that cannot be simultaneously fulfilled.
"I wanted to attend the meeting but there's a conflict in my schedule that day."
verb
°(with ‘with’) To be at odds (with); to disagree or be incompatible.
°(with ‘with’) To overlap (with), as in a schedule.