blow-by

American  

[bloh-bahy] / ˈbloʊˌbaɪ /

Or blowby

noun

Automotive.

plural

blow-bies

1. leakage of the air-fuel mixture or of combustion gases between a piston and the cylinder wall into the crankcase of an automobile.

2. a device, fitted to a crankcase, for conducting such gases back to the cylinders for combustion.

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blow-by British  

noun

1. the leakage of gas past the piston of an engine at maximum pressure

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Etymology

Origin of blow-by

First recorded in 1930–35; noun use of verb phrase blow by