The clerk replenished the shelves when they noticed they were empty.

replenished 是动词 replenish 的过去式，由前缀 re-（表示"再次"）和 plenish（来自拉丁语 plenus，意为"满的"）组成，字面意思是"再次装满"，即"补充、重新装满"的意思。