1) An amusement park near Pittsburgh, Pennsylvania.

2) The fly on your pants. Used only in the phrase "Kennywood's open!" to describe when someone's fly is open.
1)The most amazing time of my life was dropping acid and riding the Kangaroo, Phantom, Thunderbolt and Whip at Kennywood.
2) Mary: Dude. Kennywood's open.
John: Oops, sorry bout that.
by wooka wooka. November 4, 2005
One of America's best and most traditional amusement parks, located in West Mifflin, Pennsylvania. Home of the Thunderbolt, a multiple-time Best Coaster winner, and The Phantom's Revenge, consistently voted as one of the Top 10 Steel Coasters in the country. At least 5 rides in the park are National Historic Landmarks, as is the entire park itself. Home to the only "Noah's Ark" style ride left in the world, and the only racing coaster to use only one track. The tracks also cross over at a point during the ride to switch sides, but nobody seems to be able to figure out exactly where. Famous with Pittsburghers for Potato Patch French Fries, and no trip to Kennywood is complete without eating some. The park holds many special events, including fireworks on the 4th of July, a "Fall Fantasy" parade for local marching bands in mid-August, and "Fright Nights" during the month of October, where it is turned into a giant Halloween-themed park.
"Hey, we're all headed out to Kennywood for our school's picnic day."

"Kennywood's roller coasters are some of the best around!"
by Colin Farley July 4, 2006
An abandoned amusement park in West Mifflin, Pittsburgh, PA. It was vacated on September 29, 2002, when the dark and malevolent spirit behind the park's most famous ride, The Phantom's Revenge, overtook it and filled it with hellish creatures. Despite being evacuated by its staff and condemned, the park is still open to the public, as it was never officially closed.
"Hey, you wanna visit Kennywood?"

"That old place? I thought guests weren't allowed in there until October."
by Discord, God of Chaos March 23, 2018
from the Pittsburgh area, when the zipper of your jeans is down, an 'open fly'. 'Kennywood' refers to a local amusement park.
Kennywood's open! You workin' the hotdog stand?
by markimusb October 25, 2007
This saying means, "the zipper on your pants is open".There is a amusement park in Pittsburgh called Kennywood Park. If you say this to anyone from the Pittsburgh area rest assured they will check their pants immediately.
by Michael Brams April 10, 2007
The inner thigh rash that comes from walking continuously for extended periods of time. Onset of Kennywood Rash can come from hot temperatures, bad jeans, poor underwear choice, or a lack of protection, i.e. Gold Bond. Name comes from the thigh rash gotten from walking around Kennywood all damn day.
Guy 1: I need to get home and throw on some Gold Bond I have some fuckin serious Kennywood Rash.

Guy 2: Oh man fuck that go get some bond on.
by RedSharpie November 4, 2010