How can I get the "Look Up" option to find results? How can I get the "Look Up" option to find results. In Terminal, if I select a  command word then right click on it I want to use the Look Up option in the drop down menu. It is not grayed out. It just never is able to find results. Ever. 
Is the Look Up option going to tell me the meaning of the word or is it looking for it if it is in use on my computer?
I would like a way to quickly see the definition attached to the command word.
The lookup option is finding the selected word in a dictionary. The reason why you got nothing is probably because it can’t find definitions of command words.

To find a definition of a command word your best shot is to google it.