The phrase "one's entire line" refers to all the descendants or members of a family, including future generations. It basically means everyone who comes after a particular person in a family tree. Full definition
Closing a credit card closes that entire line of credit, which reduces your overall available credit. (creditabsolute.com)
Top end variants get six - airbags, ABS, reverse camera, parking assist with reverse parking sensors are available on entire line - up save for the entry level trims. (auto.ndtv.com)
It's more challenging than it sounds, as you need to draw entire lines instead of laying each tile out individually, and you need to take into account obstacles on the grid. (gamesetwatch.com)