Can You Say Lenitive?
I just found Free Rice, which is a charity site that donates 10 grains of rice to the United Nation World Food Program for each English word that you can correctly identify the meaning of.
I found it pretty hard, my vocabulary is not as large as it should be. Some of the words I was asked included: casque, duenna, newel, panegyric, oppugn, hidebound and thaumaturge. I got thaumaturge wrong, it means magician. You can use your dictionary because the site doesn’t seem to be timing your responses. But you need a pretty good dictionary since many of the words won’t be in a basic English dictionary. Have fun!