1. A stoppage in a pipeline caused by gas bubbles (especially a stoppage that develops in hot weather in an internal-combustion engine when fuel in the gas line boils and forms bubbles that block the flow of petrol to the carburettor)
   "The old car suffered from vapour lock on a hot summer day";
   - vapor lock [US]

Derived forms: vapour locks

Type of: block, blockage, stoppage

Encyclopedia: Vapour lock