1. Someone who is all talk and no action. (Comes from "yakking" and "activist," and the expression "All yak and no sack"); The opposite of a pragmatist.
2. Someone with a penchant for conjuring false hopes.
3. An expert at bluffing.
1. "She keeps saying she'll quit her job, but her co-workers know she's just a yaktivist."
2. "Whenever his father promised to take him to the zoo, he had a feeling his father was just being a yaktivist."
3. "He always wins at poker because no one can tell when he's got a good hand and when he's being a yaktivist."