point of contention

: an individual detail : item

: a distinguishing detail

: the most important essential in a discussion or matter

: to furnish with a point : sharpen

: to give added force, emphasis, or piquancy to

: to scratch out the old mortar from the joints of (something, such as a brick wall) and fill in with new material

: a point advanced or maintained in a debate or argument

: an act or instance of contending

: rivalry, competition