first-line

adjective

ˈfərst-ˈlīn How to pronounce first-line (audio)
Synonyms of first-linenext
: being the preferred, standard, or first choice
first-line treatment of tuberculosis
compare second-line

Synonyms of first-line

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Examples of first-line in a Sentence

surgery is usually not considered a first-line treatment for this type of cancer
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Nearly a third of adults with major depressive disorder fail to respond to at least two antidepressants, and half of people treated for generalized anxiety disorder do not respond to first-line treatments, studies show. — Jen Christensen, CNN Money, 29 Aug. 2026 Antidepressant medications like zuranolone and SSRIs are first-line options for PPD, while Bergink says lithium, antipsychotics and electroconvulsive therapy are effective for PPP. — Helen Carefoot, Flow Space, 28 Aug. 2026 Grover added that Nuvation Bio will likely be able to accelerate revenue growth by leveraging its existing client base, particularly if taletrectinib proves to be effective as a first-line treatment for relatively long periods of time. — Liz Napolitano, CNBC, 18 Aug. 2026 Access antibiotics are first-line treatments for common infections and should be widely available. — Peter Beyer, STAT, 18 Aug. 2026 See All Example Sentences for first-line

Word History

First Known Use

1919, in the meaning defined above

Time Traveler
The first known use of first-line was in 1919

Rhymes for first-line

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Browse Nearby Words

first light
first-line
firstling
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Cite this Entry

“First-line.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/first-line. Accessed 1 Sep. 2026.

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Medical Definition

first-line

adjective
ˈfərst-ˈlīn How to pronounce first-line (audio)
: being the preferred, standard, or first choice
first-line treatment of advanced breast cancer
compare second-line
Last Updated: - Updated example sentences
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