Frontside crooked grind is a skateboarding trick where the skateboarder approaches a rail or ledge at an angle, and grinds along it with the front trucks crooked and the back trucks straight. The front trucks are turned to the side and locked onto the rail/ledge, while the back trucks are kept straight and follow behind. This creates a diagonal grind that is visually appealing and can be challenging to execute properly.
pic https://www.instagram.com/fernandoferreiraphoto/