Will a crockpot brown ground meat?
It is possible, but only if you have the right type of crock-pot. Most crock-pots are not designed for searing and as such do not get hot enough, quickly enough to sear the meat properly. You also run the risk of cracking the ceramic pot due to uneven heating/cooling as you add the meat.

There are specific models of crock pot with a sear function. If you were to try, I would recommend that you get one of these.