whoa

Etymology

Whoa (c. 1843) is a variant of woa (c. 1840), itself a variant of wo (c. 1787), from who (c. 1450), ultimately from Middle English ho, hoo (interjection), probably from Old Norse hó! (interjection, also, a shepherd's call). Compare German ho, Old French ho ! (“hold!, halt!”).

intj

1. Stop (especially when commanding a horse or imitative thereof); calm down; slow down.
   Whoa, Nelly!
   I can see Mickie getting hot, I'm about to grab his arm, hold him back, say, Whoa, whoa, Mick, not here, it ain't worth it what happened inside just now. 2007, Ron Liebman, Death by Rodrigo, New York: Simon & Schuster, page 134
2. An expression of surprise.
   Whoa, are you serious?
   Whoa. Wait a minute, Doc. Are you trying to tell me that my mother has got the hots for me? 1985, Robert Zemeckis, Bob Gale, Back to the Future, spoken by Marty McFly (Michael J. Fox)
   Jen: Douglas has asked me to be his PA. Moss: Oh. My. God! Well, that is something and a half. His PA? How... Whoa! His PA... Shut up! His PA! Jen: It means "personal assistant". Moss: Thank you. Right, OK. September 28 2007, Graham Linehan, The IT Crowd, season 2, episode 6
3. Used as a meaningless filler in song lyrics.
   I am the type who is liable to snipe you With two seconds left to go, whoa. 2003, "Weird Al" Yankovic, eBay (song)
   And oh whoa girl, it's a shame. Oh whoa girl, it's a doggone shame. 2010, Bruce Springsteen, It's a Shame

verb

1. (transitive) To attempt to slow (an animal) by crying "whoa".
   He was whoaing the horses loudly, and they did seem to be going faster than usual—in fact, they were galloping. 1926, Josephine Demott Robinson, The Circus Lady, page 38