Is disabling an app functionally similar to unistalling it?
Not disabling and uninstalling are different things. Disabling the app will let the it stay on your phone, but it won't be functionally working in the background/foreground. While uninstalling (obviously) removes the app completely from your phone. To use it you need to reinstall the app again.

Disabling will hide your icons in your case. For disabling the app, Go to your Setting &gt; Apps &gt; All &gt; Icons_Pack_App &gt; Disable. If you want to get rid of it completely and free up space, then Settings &gt; Apps &gt; All &gt; Icons_pack &gt; Uninstall.

You can also disable and enable apps with the command,

pm enable &lt;package name&gt;
pm disable &lt;package name&gt;