Open whatever your social folder is.../includes/libs/account.install.module.php

These are the tabs inside of the 'My Account' area.

(3.20.12) HIDE TAB

$items['account/notifications'] = array(

'name'=>'Notifications',

'type'=>'tab',

'parent'=>'account'

);

Don't comment-out the whole thing, just what's inside of the array. Then save the file.

Since you've edited a module, you'll have to go to the CP > Modules, and click 'Update Modules'.

Now you should (not see) your hidden tab.