D defs.my
Entry 1 sense Webster, 1913

Clarion

/klĕr'-ē-ən/ · Clar·i·on · IPA /ˈklæ.ɹi.ən/
01 n. A kind of trumpet, whose note is clear and shrill.
  1. 1.
    A kind of trumpet, whose note is clear and shrill.
    “He sounds his imperial clarion along the whole line of battle.” — E. Everett.