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first-line

American  
[furst-lahyn] / ˈfɜrstˈlaɪn /

adjective

  1. available for immediate service, especially combat service.

    first-line troops.

  2. of prime importance or quality.


first-line British  

adjective

  1. acting or used as a first resort

    first-line treatment

    first-line batsmen

"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

Etymology

Origin of first-line

First recorded in 1895–1900

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

Researchers noted that these reductions are similar to results seen with some first-line blood pressure medications.

From Science Daily May 10, 2026

Each time, the first-line representative said no, suggesting something like, “If you can’t afford to pay it now, set up a payment plan or apply for financial assistance.”

From Slate Apr. 25, 2026

Nektar stock jumped 26% after positive trial results, with analysts raising price targets and expecting first-line treatment potential.

From Barron's Apr. 20, 2026

Some experts believe it is a debilitating reaction to steroid creams - the first-line treatment for many of the eight million people who have eczema in the UK.

From BBC Mar. 28, 2026

For now, the cost of treating MDR-TB is approximately 475 times greater than treating first-line TB, according to PIH.

From "Mountains Beyond Mountains" by Tracy Kidder and Michael French

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