Adj: An act that would commonly be performed by a bitch (definition #4). Used to describe the act itself. May be used regarless of gender of implied person.
"Dude, she slashed your tires? That's bitchenistic!"
Putting two praying mantis' in a bowl until one ate the other would be bitchenistic.
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.