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Glite Dictionary
petcock

petcock

1 9.9
A small valve that lets liquid or air out of a tank
  • noun
  • /ˈpɛtˌkɒk/
  • Specialized
translation icon : grifo
  • Before changing the coolant, make sure to open the petcock at the bottom of the radiator.
  • open the petcock

Examples

  • The mechanic released air from the tank by turning the petcock.

  • The mechanic opened the petcock to drain the oil.

  • Please close the petcock tightly after draining the oil.

  • Make sure the petcock is closed before starting the engine.

  • To prevent water from collecting, make sure to open the petcock at the bottom of the tank.

  • He turned the petcock to release trapped air from the radiator.

  • After filling the reservoir, close the petcock to stop the flow of liquid.

Synonyms

cock
vspetcock
9 8.6

A valve you turn to let water or gas flow

is smaller and mainly drains liquids or releases air
stopcock
vspetcock
  • Specialized
1 7.7

A valve you turn to control the flow of water in a pipe

is smaller and used for draining or letting air escape
turncock
vspetcock
  • Archaic
9.9

A valve with a handle you turn to stop or let water flow

is smaller and used to drain liquids or to release air
seacock
vspetcock
  • Specialized
8.8

A valve in a boat's hull that controls water entering or leaving

is smaller and mainly used to drain or to let air escape

Surface Forms

petcock singular
petcocks plural

Etymology

Petcock comes from old parts that mean 'small' (pet-) and 'tap' (cock), so the name is like a 'small tap'. That's why a petcock is the little valve you open to drain liquid or let air out.