first-line
adjective
: being the preferred, standard, or first choice
first-line treatment of tuberculosis
compare second-line
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
Their defensive group might be the best in the tournament, and the emergence of Leo Carlsson as an elite first-line center over the last few months fixes the roster’s most significant long-term issue.
—
Sean Gentille, New York Times, 2 Jan. 2026
The result is that first-line antibiotics become ineffective for simple infections so that stronger, more expensive, intravenous-only drugs become required.
—Neil Gaffin, STAT, 29 Dec. 2025
The first-line preventive drug for acute mountain sickness, or AMS, is a drug called acetazolamide, sold under the trade name Diamox.
—Alex Hutchinson, Outside, 23 Dec. 2025
However, it's not typically considered a first-line option.
—Heather Jones, Verywell Health, 1 Dec. 2025
See All Example Sentences for first-line
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Sean Gentille, New York Times, 2 Jan. 2026
The result is that first-line antibiotics become ineffective for simple infections so that stronger, more expensive, intravenous-only drugs become required.
—Neil Gaffin, STAT, 29 Dec. 2025
The first-line preventive drug for acute mountain sickness, or AMS, is a drug called acetazolamide, sold under the trade name Diamox.
—Alex Hutchinson, Outside, 23 Dec. 2025
However, it's not typically considered a first-line option.
—Heather Jones, Verywell Health, 1 Dec. 2025
See All Example Sentences for first-line
Cite this Entry
“First-line.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/first-line. Accessed 10 Jan. 2026.
Copy CitationMedical Definition
first-line
adjective
: being the preferred, standard, or first choice
first-line treatment of advanced breast cancer
compare second-line
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