- a border; dividing line; line of demarcation
- an indeterminate position between two conditions or qualities: the borderline between friendship and love
- on the edge of one category and verging on another: a borderline failure in the exam
WordReference Random House Learner's Dictionary of American English © 2026
bor•der•line /ˈbɔrdɚˌlaɪn/USA pronunciation
n. [countable]
adj. [before a noun]
- Also, ˈbor•der ˌline. a boundary line;
something marking a division. - an uncertain condition between one situation and another:[usually singular]at the borderline of sleep and wakefulness.
adj. [before a noun]
- on or near a border or boundary.
- not quite meeting accepted standards:borderline alcoholism (= in between alcoholism and its absence). I had several borderline applications to decide on; should we interview them or not?
Collins Concise English Dictionary © HarperCollins Publishers::
borderline /ˈbɔːdəˌlaɪn/ n
bor′der line′,
bor•der•line (bôr′dər līn′),USA pronunciation adj.
n.
- boundary line;
frontier.
- 1865–70
bor•der•line (bôr′dər līn′),USA pronunciation adj.
- on or near a border or boundary.
- uncertain;
indeterminate;
debatable:not an alcoholic, but a borderline case. - not quite meeting accepted, expected, or average standards.
- approaching bad taste or obscenity:He made several borderline remarks that offended them.
n.
- Psychiatrya person suffering from borderline personality.
- border + line1 1865–70
- 3. marginal, problematic, uncertain, doubtful.
'borderline' also found in these entries (note: many are not synonyms or translations):