We found an online vocab game at FreeRice.com which will donate 20 grains of rice to the United Nations World Food Program to help reduce world hunger for every word a player get right.
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FreeRice.com is a not-for-profit organization and the rice is paid for by the advertisers whose names you see on the bottom of your vocabulary screen. Through their advertising at FreeRice, these companies support both learning (free vocabulary for everyone) and reducing hunger (free rice for the hungry).
Play for free to help feed the hungry.