astonisher

noun5

1. •
   Something that astonishes; an astonishing thing or event.

   • It [this court decision] is the first of its kind; it is an astonisher in legal history; it is a new wonder of the world — 1858
2. •
   Someone who astonishes.

   • […] God, before whom all Nations are as nothing, thou Astonisher of all Flesh, thou art even too Wonderful for me, — 1675
3. •
   A headline or lead (introductory paragraph) designed to capture attention through a surprising statement.

   • He reveled in socking the reader right in the eye with an “astonisher.” — 1969
4. •
   (US) An exclamation mark, the punctuation mark “!”.

   • “ […] Nothing whatever” ! (the italics are “S. S. C.’s,” the “astonisher” is mine.) — 1874
5. •
   (US) A short line of smaller type above (or sometimes below) the main headline of an article, usually placed flush-left.