French word aplanir comes from French plan, French a-, French -ir (A suffix forming infinitives of many verbs.)

Detailed word origin of aplanir

Dictionary entry	Language	Definition
plan	French (fra)	Planar (cinema) shot. Map (schematic maps of streets, subways, etc.). Plan. Plane (both flat surface and mathematical plane).
a-	French (fra)	A prefix forming words, especially verbs, that denote entering a state, making progress toward a goal, or the like. A-, non-, -less.
-ir	French (fra)	A suffix forming infinitives of many verbs.
aplanir	French (fra)	To level, even out.

Words with the same origin as aplanir