first-line

adjective

ˈfərst-ˈlīn 

: being the preferred, standard, or first choice

first-line treatment of tuberculosis

compare second-line

Synonyms of first-line

• selected
• select
• favorite
• preferred
• favored

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

In the early 1990s, it was demonstrated that the PSA blood test could be used as a first-line screening test for prostate cancer. — Jacqueline Howard, CNN Money, 12 Nov. 2026

Antidepressant medications are a first-line treatment for SAD, along with light therapy. — ABC News, 4 Nov. 2026

The study, which was presented at a major cancer meeting called the European Society for Medical Oncology Congress, did not test whether the combination was better than other first-line treatment approaches. — Annika Kim Constantino, CNBC, 24 Oct. 2026

Pelvic floor therapy becomes a first-line referral, not a last resort. — Hanna Wickes, Charlotte Observer, 19 Oct. 2026

Word History

First Known Use

1919, in the meaning defined above

Rhymes for first-line

• affine
• airline
• align
• aline
• assign
• baseline
• beamline
• benign
• bloodline
• bovine
• brucine
• byline

Medical Definition

first-line

adjective

ˈfərst-ˈlīn 

: being the preferred, standard, or first choice

first-line treatment of advanced breast cancer

compare second-line