Sayyiduna Qays bin Abi Gharazah (may Allah be pleased with him) said: We used to buy and sell in the market of Madinah and call ourselves brokers. Then the Messenger of Allah (peace and blessings be upon him) came to us and gave us a better name than the one we used to give ourselves, and said: "O company of traders, idle talk and oaths get mixed into this buying and selling, so mix it with some charity."
The narrator's explanation: This word means to mix it, to blend it.
Hadith Referenceالمعجم الكبير للطبراني / باب القاف / 16007