What is the meaning of Borderline?

Nearly; not clearly on one side or the other of a border or boundary, ambiguous.

Of questionable taste or acceptability; approaching bad taste.

Exhibiting borderline personality disorder.

Nearly; not entirely but nevertheless to a great extent.

A boundary or accepted division; a border.

Short for borderline personality disorder.

A person who has borderline personality disorder.

To border, or border on; to be physically close or conceptually akin to.

someone with borderline personality disorder

Source: wiktionary.org