give away the farm

To give another party all or the majority of the benefits in a deal or transaction. You were so eager to sign a contract with a manufacturing partner that you ended up giving away the farm. Now they're going to be the ones to get all the profits from sales! Make sure you don't give away the farm during negotiations. You don't want to find yourself at a disadvantage by the end of things. My lawyer sure gave away the farm in our divorce proceedings. I have very little left to my name!