What is the greek word for Richard?

There isn't a direct Greek equivalent of the name Richard. Names are translated based on meaning, not direct sound. Richard comes from the Germanic elements *ric* (power, ruler) and *hard* (brave, strong). To find a Greek equivalent, you'd need to find Greek words with similar meanings and create a name from them. There are many possibilities, depending on which aspect of "Richard" you want to emphasize. There's no single "correct" answer.