To be covetous of something is to want it and to be a little jealous of anyone who has it. The advertising industry’s goal is to make you covetous of the things that other people have — that way, you'll buy them.
If you feel the desire to own an object, specifically something that your friend owns, you are covetous of it. You might be covetous of her new high-speed digital camera. There is a commandment in Christianity about not feeling covetous toward your neighbor’s spouse: this could apply to a situation when you might find yourself attracted to your friend’s girlfriend, boyfriend, husband, or wife. Best to smother those feelings, if you want to keep that friendship.
