(informal) An individual who has borderline personality disorder.

plural of borderliner

nearly; not clearly on one side or the other of a border or boundary, ambiguous. / Showing bad taste. / Exhibiting borderline personality disorder.

Nearly; not entirely but nevertheless to a great extent.

(countable) A boundary or accepted division; a border. / (uncountable) Short for borderline personality disorder. / (countable) An individual who has borderline personality disorder.

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

plural of borderline

The quality of being borderline.

simple past tense and past participle of borderline

present participle of borderline