For me, 'moody' means being/acting out of character (not being true to what I really am or want). So, I'm moody when:
- I'd rather stay at home, watching romantic comedies on a Friday night instead of hang out with my friends.
- I don't answer the phone when my friends call, even though I was hoping someone would call.
- I begin conversations trying to bait someone into an argument.
- Say something that will obviously give away my moodiness and then say I don't want to talk about it when someone asks.