One who treats friends and the relationships that define them as expendable commodities to be consumed when convenient, depleted, used-up and eventually tossed-away without concern for the norms of social behavior and interaction.
What? Janice convinced you to loan her your car so she could go to her NA meetings? She did the same thing to me last summer, but in that case it was for her domestic counseling sessions, and she actually side-swiped an ice cream truck on the last day and returned my car to me damaged - I haven't heard from her since. Watch-out, girlfriend! She is such a friendsumer!