I don't know what you mean by the iCloud icon. There is no icon/app named iCloud, to the best of my knowledge. {With the exception of the icon in the Settings app}
If you can give a better description of what it did, maybe I can make a better guess, but in the mean time:
You can not delete a native app. Some apps will disappear from the Home Screen if you turn them off in Restrictions (Settings > General > Restrictions). If you set restrictions, do not forget the password. It's a pain to recover from this.
An app may also be hiding in a folder. Check them all.
If it was an app you purchased, open the App Store and choose the Purchased tab. Any app you have purchased will show up there, whether currently on the iPad or not. If it's not on the iPad, you can download it again.