letting go and getting rid of something,
Explanation:
The word that is mentioned in the question is wrong and the actual word is "discharged". That being said in the following sentence from the boston tea party ...
"Others raised them to the railing and discharged their contents overboard"
The word discharged is being used to say that the individuals are letting go and getting rid of something, in this case by throwing it overboard the ship where it will be gone. In this scenario, what they are getting rid of is their content with their actions.