While Android 4.0 (aka Ice Cream Sandwhich) introduced the feature to "disable" some system apps and bloatware (which can be done from Settings→Apps→Manage Apps by selecting the corresponding app and hit the "Disable" button, when that one is not grayed out), this does not work for all apps -- and is not available prior to Android 4.x.
But long before ICS was even announced, apps like e.g. Titanium Backup allowed the user of a rooted device to do the very same, but for all system/bloatware apps. It then was (and still is) called "freezing an app". Of course, if the user wishes he can "un-freeze" a frozen app at any time.
Please do not confuse this with a "hanging app" which no longer responds to user input -- which is a completely different issue called "ANR" (Application Not Responding).
- bloatware: Apps which manufacturers think to "make users happy", but hardly anyone really wants to use. Still, they come pre-installed on our devices, and (with few exceptions) cannot be un-installed without rooting the device in question. Luckily, they can be disabled with Android 4+ -- or instead of uninstalling them, they can be frozen.
You can use this tag in conjunction with freeze-app if your issue is about freezing bloatware apps.
Unrelated, but similar sounding
- system-freeze: when the entire system stops responding to user input.