File under “Plenish, Re-”: Replenish was originally not a synonym of resupply.
Why can you replenish something but not plenish it in the first place? Because there is no sense of “again” or of repetition in the original meaning of the word replenish. That word came to English in the 1300s from Old French repleniss-, and it simply meant “to stock” or “to fill up” (in fact, replenished —indicating “full”—arrived before the verb replenish did). But mistaking the re- as the prefix meaning “again,” we began by the early 1600s to use the word to mean “restock.”
You’d think that that change in meaning would leave a void that would have to be, um, replenished, and that back-forming plenish might fill the bill of lading. And the word plenish was indeed used, though briefly and rarely and not in reaction to the shift in the word replenish. Ultimately, I suppose that the variety of plenish synonyms like stock and supply made the void left by replenish pre-replenished.
Bill Brohaugh
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