1.VerbTo choose (something) in exchange for something else, where having both at once is not an available option.
"In the entry-level product category, the engineers had to trade off maximal durability for affordable upfront cost."
2.VerbTo choose among options, where having them all at once is not an available option.
"Part of being a competent engineer is knowing how to trade off appropriately among mutually exclusive options, depending on the specified requirements for each design."