BORDERLINE
borderline, marginal
(adjective) of questionable or minimal quality; “borderline grades”; “marginal writing ability”
Source: WordNet® 3.1
Etymology
Adjective
borderline (comparative more borderline, superlative most borderline)
nearly; not clearly on one side or the other of a border or boundary, ambiguous.
Showing bad taste.
Exhibiting borderline personality disorder.
Adverb
borderline (not comparable)
nearly; not entirely but nevertheless to a great extent
Noun
borderline (plural borderlines)
A boundary or accepted division; a border.
An individual who has borderline personality disorder.
Verb
borderline (third-person singular simple present borderlines, present participle borderlining, simple past and past participle borderlined)
(transitive) To border, or border on; to be physically close or conceptually akin to.
Source: Wiktionary