Sentence:  In the mining industry, the owner of semi-processed material might enter into a <WSD>tolling agreement</WSD> with a smelter or refiner to turn his semi-processed product into metal 
Meaning of the word marked with <WSD> tags:  An agreement by a toller with an owner of raw materials to process the raw material for a specified fee ("toll") into a product with the raw material and the product remaining the property of the provider of the raw material.