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.


a person suffering from borderline personality.

Origin of borderline

First recorded in 1865–70; border + line1

Synonyms for borderline Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for borderline

Contemporary Examples of borderline

Historical Examples of borderline

  • It was so poignant a sensation that it crossed the borderline into pain.

    The Ideal

    Stanley Grauman Weinbaum

  • Between prescience and imagination the borderline is ill defined.

  • Why had she ventured back on to the borderline of this life that had once been hers?

    To Love

    Margaret Peterson

  • The old man was upon that borderline between the living and the dead.

  • Going from Stirling to Crieff we crossed the borderline of the Highlands.

    The Heather-Moon

    C. N. Williamson and A. M. Williamson

British Dictionary definitions for borderline



a border; dividing line; line of demarcation
an indeterminate position between two conditions or qualitiesthe borderline between friendship and love


on the edge of one category and verging on anothera borderline failure in the exam
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for borderline

1869, "strip of land along a frontier," from border (n.) + line (n.). As an adjective meaning "verging on" it is attested from 1907, originally in medical jargon.

Online Etymology Dictionary, © 2010 Douglas Harper