Something that is borderline is only just acceptable as a member of a class or group.
Some were obviously unsuitable and could be ruled out at once. Others were borderline cases.
一些显然不合适,可以马上被排除。另一些勉强合格。
borderlines
The borderline between two different or opposite things is the division between them.
a task which involves exploring the borderline between painting and photography.
一项涉及探索绘画与摄影之间界线的任务。