How to grep a string that do no cantain another substring?
There is the solution:
$ ls | grep -ivE 'unimous'
Here is a practical example of using it. If you want to find all the files with names containing 'wireshark' and without 'unimous', and then delete all of them:
$ sudo updatedb $ locate wireshark | grep -viE 'unimous' | xargs sudo rm -rf