A boundary or accepted division; a border.
She lives on the borderline between reality and madness.
An individual who has borderline personality disorder.
To border, or border on; to be physically close or conceptually akin to.
Nearly; not clearly on one side or the other of a border or boundary, ambiguous.
I would rather hire a talented layman than a university graduate with borderline qualifications.
Showing bad taste.
Your borderline remarks about my aunt's dress destroyed my evening.
Exhibiting borderline personality disorder.
Nearly; not entirely but nevertheless to a great extent
He is borderline hypoglycemic and needs to monitor his sugar intake.