Students in my classes know that, for Latin, I am a big fan of Whitaker’s Words.
Students in my Greek classes know that I haven’t found anything quite like Whitaker’s Words for Greek.
There’s this: http://www.perseus.tufts.edu/hopper/
It’s the best I have found.
However, this morning, I discovered this: http://www.motorera.com/greek/lexicon/a.html
Doesn’t really look that great, but maybe it will turn out to be. We will see.