Unexpected change in direction of progression in life or any other activity.
Going off the rails.
Can be positive or negative.
Person A: "Did you hear about whats-her-face? She's working for McDonalds now instead of her Government job."
Person B: "Sounds like she's going sidewards."
"Her life is sidewards now that she's won lotto"
1) to turn both sideways and backwards
2) To turn sideways except cooler
"I just turned my head sidewards and it was rightside up"