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 of pileup

• accumulation
• collection
• pile
• jumble
• mixture
• gathering
• assemblage
• cumulation

Examples of pileup in a Sentence

A five-car pileup slowed traffic.

a pileup of e-mail messages that needed to be dealt with

Recent Examples on the Web

Staffers also contacted the Colorado State Patrol, as the 70-car pileup happened, to alert law enforcement. —Alan Gionet, CBS News, 17 Apr. 2026

Further investigation revealed that the pileup occurred only on the eastbound lanes of Interstate 70, the Colorado State Patrol said in a statement. —Thao Nguyen, USA Today, 16 Apr. 2026

The sheriff’s office indicated that all of those earlier incidents had been cleared before the major 75-vehicle pileup unfolded nearby on I-70 eastbound near mile marker 216. —Bonny Chu, FOXNews.com, 15 Apr. 2026

The pileup Tuesday prompted officials to close the eastbound side of Interstate 70 in Clear Creek County, about 50 miles (80 kilometers) west of Denver, the Colorado State Patrol said in a statement. —ABC News, 14 Apr. 2026

Word History

First Known Use

1900, in the meaning defined at sense 1

Rhymes for pileup

• buttercup
• backup
• blowup
• breakup
• buildup
• checkup
• cleanup
• holdup
• hookup
• lineup
• lockup
• makeup