Final answer:
The type of context clue that reveals the meaning of the word sous vide is a definition context clue.
Step-by-step explanation:
The type of context clue that reveals the meaning of the word sous vide in the given sentence is a definition context clue. In this context, the phrase 'which is cooking food in an airtight bag in boiling water' provides a definition or explanation of what sous vide means. It helps the reader understand that sous vide refers to a method of cooking food in an airtight bag in boiling water.