pileup
noun
pile·up ˈpī(-ə)l-ˌəp 
1
: a collision involving usually several motor vehicles
2
a
: a jammed tangled mass or pile (as of motor vehicles or people) resulting from collision or accumulation
b
: accumulation
Synonyms
- accretion
- accumulation
- assemblage
- collection
- cumulation
- cumulus
- gathering
- lodgment
- lodgement
See all Synonyms & Antonyms 
Example Sentences
A five-car pileup slowed traffic. a pileup of e-mail messages that needed to be dealt with
Recent Examples on the Web Electric-vehicle startups had a rip-roaring 2021 as investors placed bets on which would be the next Tesla Inc. TSLA 3.38%▲ This year has been more like a pileup on the track. 
Ben Foldy, WSJ, 7 Sep. 2022 Dunwoody police said the initial investigation indicated that a driver tried to dart around a vehicle in front of them, causing a four-car pileup that resulted in the truck fire. Henri Hollis, ajc, 1 Sep. 2022 At least six people, including two children, were killed Friday when a dust storm with winds around 60 mph hit a Montana highway, causing a massive pileup of vehicles, authorities said. Washington Post, 16 July 2022 While the Tour ultimately dropped its lawsuit against the woman, she was ultimately fined €1,200 ($1,357, at the time) for causing the pileup, according to the BBC. Tommy Mcardle, PEOPLE.com, 8 July 2022 Initial reports were a 20-car pileup on 408 westbound near Andes Ave, however, the updated number was 43. NBC News, 16 Apr. 2022 Cruz’s injury, to his thumb, was fluky; McCloud’s leg was mangled in a pileup. Michael Lev, The Arizona Republic, 5 Aug. 2022 Six people are dead in a Montana highway pileup Friday that may have been caused by a dust storm, authorities said. Dennis Romero, NBC News, 16 July 2022 Authorities said there were injuries in the pileup. Washington Post, 16 July 2022 See More
Ben Foldy, WSJ, 7 Sep. 2022 Dunwoody police said the initial investigation indicated that a driver tried to dart around a vehicle in front of them, causing a four-car pileup that resulted in the truck fire. Henri Hollis, ajc, 1 Sep. 2022 At least six people, including two children, were killed Friday when a dust storm with winds around 60 mph hit a Montana highway, causing a massive pileup of vehicles, authorities said. Washington Post, 16 July 2022 While the Tour ultimately dropped its lawsuit against the woman, she was ultimately fined €1,200 ($1,357, at the time) for causing the pileup, according to the BBC. Tommy Mcardle, PEOPLE.com, 8 July 2022 Initial reports were a 20-car pileup on 408 westbound near Andes Ave, however, the updated number was 43. NBC News, 16 Apr. 2022 Cruz’s injury, to his thumb, was fluky; McCloud’s leg was mangled in a pileup. Michael Lev, The Arizona Republic, 5 Aug. 2022 Six people are dead in a Montana highway pileup Friday that may have been caused by a dust storm, authorities said. Dennis Romero, NBC News, 16 July 2022 Authorities said there were injuries in the pileup. Washington Post, 16 July 2022 See More Word History
First Known Use
1900, in the meaning defined at sense 1