The phrase "what a knockout" is correct and usable in written English.
It is typically used as an expression of admiration or respect for someone or something. For example, "What a knockout dress she's wearing tonight!".
That is what a knockout is, after all — a man dislodged from his senses (temporarily, with any luck) from a brutal blow to the head.
And there are deaths by "Darwinian Events," including this account, published under the title "What a Knockout," of a young girl's death: "A car knocked down and killed a teenage girl while the driver was distracted by a billboard advertising women's lingerie.
But let's not let the anticlimax overshadow what a knockout of tension "Internment" was.
But what a peppy knockout Peggy was! — cheerleader, hockey star, May Queen, RN.
What is a knockout punch and how does it work?A knockout blow is a form of cerebral concussion, a common scourge in other sports such as American football, football and hockey.
When such large datasets are available, interesting questions can be asked and answered in terms of what a particular gene knockout event can cause and in what context.
But the momentum Schickler gathers with what is literally a knockout ending doesn't go anywhere.
Best misdirection in this grid in my opinion was 14 Across's "What might be a knockout?" for OPIATE.
Cinematographer Maryse Alberti (whose credits include The Wrestler) dances nimbly around the fights, capturing one in what looks like a knockout single take, while Tony Bellew's "Pretty" Ricky Conlan (from "Liverpool, England") makes a strong fist of being a genuinely dangerous opponent.
He's battered and bloodied from being beaten and bullied, but suddenly his opponent is flat-footed, caught off guard, and your guy is winding up for what could be a knockout punch.
What we want is a knockout — at least, that's what we think we want.
