If a rate or amount levels off, it stops rising or falling and stays at the same level.

House prices now seem to be levelling off after the steep rises of the last few years. 房价经过这几年的飙升后目前似乎已趋于稳定。

Unemployment rose to ten percent and then levelled off. 失业率在上升至10%后一直处于稳定状态。