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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:

About half of patients with metastatic melanoma will get worse on first-line immunotherapies within a year, at which point they have scant options.

From The Wall Street Journal ● Jul. 28, 2026

I was told that there were a variety of first-line drug treatment options available on the NHS, including Doxylamine Succinate and Pyridoxine Hydrochloride, a drug which goes by the brand name Xonvea in the UK.

From BBC ● Jun. 29, 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

Now she was being retreated with the same first-line regimen and, of course, Farmer knew, as he put his stethoscope to her chest, she was only getting sicker.

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

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