borderline

American  

[bawr-der-lahyn] / ˈbɔr dərˌlaɪn /

adjective

1. on or near a border or boundary.

2. having an uncertain, indeterminate, or debatable status.

   He was a borderline case for admission to the program—please encourage him to apply again next year.

3. not quite meeting accepted, expected, or average standards.

   Discover specific how-to strategies for turning a borderline student into a confident achiever.

   Synonyms:

   marginal, unsure, precarious, doubtful

4. approaching bad taste or obscenity.

   He made several borderline remarks that offended them.

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noun

1. null border line.

   1. a border or boundary.

      The town of Tiverton, Rhode Island, rests on the once-disputed Massachusetts borderline.

   2. a notional dividing line.

      Often the borderline between safety and toxicity is very small, and every year thousands of fish die as a consequence of chemical overdosing.

2. a person with borderline personality disorder.

borderline British  

/ ˈbɔːdəˌlaɪn /

noun

1. a border; dividing line; line of demarcation

2. an indeterminate position between two conditions or qualities

   the borderline between friendship and love

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adjective

1. on the edge of one category and verging on another

   a borderline failure in the exam

Etymology

Origin of borderline

First recorded in 1865–70; border + line ¹

Example Sentences

“The calcium score has value in borderline or intermediate-risk zones,” says Blaha.

From The Wall Street Journal • Mar. 30, 2026

For people with borderline or moderate risk, clinicians may use extra tests to guide decisions.

From Science Daily • Mar. 29, 2026

A former engineer at Meta, who we are calling Tim, said that, as the company sought to compete with TikTok, more borderline harmful content was allowed on the site.

From BBC • Mar. 16, 2026

It’s a communication style or, more accurately, a manipulation tactic used by people who have a borderline personality disorder.

From MarketWatch • Mar. 3, 2026

Khanum Taheri’s chaperoning made our meetings, if not gossip-proof, then less gossip-worthy, even if her borderline fawning on me clearly embarrassed Soraya.

From "The Kite Runner" by Khaled Hosseini

Related Words

• marginal