D defs.my
Entry 2 senses Webster, 1913

Stunner

/stŭn'-ẽr/ · Stun·ner · IPA /stˈʌnər/
01 n. One who, or that which, stuns.
  1. 1.
    One who, or that which, stuns.
  2. 2.
    Something striking or amazing in quality; something of extraordinary excellence.[Slang]