If your wheel has play in it when you move the tire holding from top and bottom then the wheel bearing is shot, replace it. If you are only feeling play when holding the tire left and right then turn the wheel so you can see the tie rod and ball joint, now move the wheel and see what part is loose.
If the joint working balls are pitted and their cage is worn out then you need to change the joint - its too late for any regreasing. Do not use general purpose grease in there as its not meant to take the extreme beating that a CV joint places in its grease. Use correct cv joint grease only.