The phrase "lot line" refers to the boundaries that define the edges of a piece of land or property. It helps to determine where one property ends and another begins. Full definition
We pulled into a parking lot lined with brand new vehicles and all I could think about was what happens when a hail storm rolls through. (ohladycakes.com)
It also helps a seller to have an idea of property lot lines in the event there is no survey. (www2.geowarehouse.ca)
Their name comes from the fact that there is no physical lot line between the homes. (themortgagereports.com)