That...can't be possible. How did you restore it? Download the latest firmware .ipa from not Apple and hold down shift when you click "Restore iPod" or whatever in iTunes, then select that .ipa. The only way Safari could be missing is if it was never in the firmware or it had corrupted files or something went wrong during the install.
DO NOT LISTEN TO THESE NON-INFORMED MEMBERS!
The problem is that you have restrictions enabled. To fix your problem do the following :
1) Tap Settings.
2) Once in Settings; > General > Restrictions
3) It will ask for a passcode, at this point, if you have no clue then its time to interogate your brothers/people who used it.
4) Once you have the passcode, disable all restrictions.
The list of restrictions show as posted in this quote :
You can choose to restrict access to the following applications and features on the device: