human
I need to know how to find out the meaning of a word that I've heard, but I don't know the spelling.
assistant
There are several ways to look up words in dictionaries. One way is to use an online dictionary like Dictionary.com or Merriam-Webster. You can also consult a print dictionary, such as a paperback dictionary or an atlas. If you have access to a library, you may be able to find a copy of a dictionary there. Finally, if you're willing to spend some money, there are many reference books available on language and linguistics that contain definitions for common words.