Forward slash doesn't work when in terminal... works in every other application
Let's try a few things.

First, make sure "Secure Keyboard Entry" under the Terminal menu does not have an arrow next to it.

Second, go to Terminal > Preferences > Settings > Keyboard and make sure that forward slash is not defined in the list. Under 'Advanced' make sure 'Declare terminal as:' is set to one of the xterm settings, preferably 'xterm-256'. In the same dialog make sure 'Character encoding:' is set to 'Unicode (UTF-8)'.

Go to System Preferences > Keyboard > Shortcuts and make sure that '/' is not set to do anything in 'Services' and 'App Shortcuts'.

Now try it and see if you still have the same problem.