having a surface without slope, tilt in which no part is higher or lower than another
同义词：flat, level, plane
planer详细解释
plan.er
n.（名词） One that planes, especially a machine tool that is used to smooth or finish the surfaces of wood or metal. 刨机，刨床：刨平东西的工具，尤其指用来磨平或抛光木材或金属表面的机床工具 Printing A smooth block of wood used to level a form of type. 【印刷术】 平版木：用来使版面的形式平整的光洁木块
