First-line

adj

adj ·Rare ·Advanced level

Definitions

Adjective
  1. 1
    Of first resort. not-comparable

    "The embankment was the first-line defense against the flood."

  2. 2
    Of prime quality or importance. not-comparable
  3. 3
    At the lowermost supervisory level. not-comparable

    "first-line manager"

Example

More examples

"Penicillin is a first-line treatment for bacterial infections, but doesn't work against viruses."

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Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.