"Closet sin, sin commited in privacy. Bp. Hall." as seen below
To add to Webster 1913s definitions, closet can refer to anything committed in privacy. To be a closet something, all you have to do is represent yourself as one person while really being another. Does this sound confusing? Something of an explanation follows...
I often accuse one of my friends of being a closet Trekkie. He watches Star Trek secretly when nobody is around. I find his hidden appreciation for Star Trek endearing, but I encourage him to be his true self, and not fear being caught watching Star Trek. I believe myself to be a closet messy person (not to be confused with a messy closet person), having a neat and orderly bedroom to display and a nice workspace on my desk but dishevelled drawars and random clothing under the bed! I often believe others are closet 'N Sync or Britney fans. Of course, I don't condone this kind of deception and deceit. Come out of the closet! Proclaim your love for cheesy Mentos Commercials and elevator music! Be revealed!
See also: Closet Top 40 Listener, Closet Goth, Closet Nodesheller