pileup

1 ENTRIES FOUND:
pileup /ˈpajəlˌʌp/ noun
plural pileups
pileup
/ˈpajəlˌʌp/
noun
plural pileups
Britannica Dictionary definition of PILEUP
[count]
1 
: an accident in which several or many vehicles crash into each other
2 
: a large amount of something that has increased gradually over a period of time — see also pile up at 2pile