Layover is an extreme form of elevation displacement or foreshortening in which the top of a reflecting object, such as mountain, is closer to the radar (in slant range) than are the lower parts of the object. The image of such a feature appears to have fallen over towards the radar. Also defined as the displacement of the top of an elevated feature with respect to its base on the radar image. The peaks look like dip-slopes. The effect is more pronounced for radars having smaller incidence angle.

https://earth.esa.int/handbooks/asar/CNTR5-5.html