unlocking an icloud locked iphone 4?

Not without the real credentials your Uncle used to lock the phone. Your Uncle needs to unlock the phone, or its useless to you. You're going to find that an iPhone 4 is not useful for much. It is so out of date, most apps will be incompatible with it today.

If it is Activation Locked, give it back to your uncle, and ask him to unlock it.

Normally, you should prepare an iPhone for transfer. In this case, the iPhone in question is so old that if your uncle follows all of the recommended steps, you may delete apps that you can't get back from the App Store – because the developers will have replaced them with newer versions that require something higher than iOS 7.1.2.

In this case, you might want to have him sign out of his Apple ID without fully resetting the phone. Then you could sign in with your Apple ID. (Just guessing here – other people may have better ideas on how to proceed.)

What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support

lobsterghost1 wrote:

You're going to find that an iPhone 4 is not useful for much. It is so out of date, most apps will be incompatible with it today.

I could be mistaken, but it looks to me like the iPhone 4 is a 2G or 3G phone – there was a GSM one and a CDMA one, but MacTracker's descriptions don't mention any LTE (4G) radio coverage.

In the U.S., phone carriers have shut off virtually all of their 2G and 3G networks. (There is a thread somewhere about T-Mobile maintaining an unsupported 3G network in parts of the U.S. for a few months more. That is the exception that proves the rule.)

So an iPhone 4 would basically be useful

• As a music player (iPod)
• As a device for storing things like calendars and notes
• As a device for playing whatever games are already installed on it

and not much more than that.

You are correct. iPhone 4 was NOT LTE and if the phone is in the US, it will not connect to any carrier networks in the US. So, using it as a phone won't work.