The phrase "slide outs" refers to a feature in vehicles or structures that allow a section of the space to move outward, increasing the available room inside. Full definition
There is even a hidden mesh in the leg rest for a newborn as an extra safety feature which will prevent a baby from sliding out of the seat. (momsstrollerreviews.com)
They hold the front up fine, but the ones I have used have a tendency to slide out from under the wheels when you are trying to get up them. (humblemechanic.com)
Usually when I use a hardware slide out keyboard the keys are too small and too close together. (littletechgirl.com)