It stands for "giggling quietly to myself"; Used during IM conversations in place of lol because no one really laughs out loud when they write lol anymore

Also used when something is just not hilarious enough to warrant a lol, a lmao, or a rofl.

Anatidaephobia is defined as a pervasive, irrational fear that one is being watched by a duck. The anatidaephobic individual fears that no matter where they are or what they are doing, a duck watches.

Anatidaephobia is derived from the Greek word "anatidae", meaning ducks, geese or swans and "phobos" meaning fear.