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

The drug is being positioned as a first-line treatment option. — Justin Zacks, CNBC, 4 June 2026

And just as with Bessie and Bluebell, first-line treatment doesn’t always start with a pill. — Pat Beall, Sun Sentinel, 12 June 2026

But not everyone responds to this line of treatment, and those who fail first-line therapies are often left without next steps. — Freda Kreier, Hartford Courant, 30 May 2026

Right now, chemotherapy is still recommended as a first-line treatment for patients with advanced pancreatic cancer. — Erika Edwards, NBC news, 31 May 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