Q: Your piece on the use of “full” in reference to eating mentioned in passing the use of “full” to describe, among other things, a sail filled with wind. This got me thinking about the link between “full” and “fill.” Would you comment on it?
A: The words “full” and “fill” have an ancestral connection that not only predates English but is older than written language.
Far back in prehistory, according to the Oxford English Dictionary, the ancestor of “fill” was derived from the ancestor of “full.” So etymologically, to “fill” is to “make full.”
As John Ayto’s Dictionary of Word Origins explains, a prehistoric Germanic adjective that linguists have reconstructed as fullaz (full) was the source of a corresponding verb, fulljan (fill).
These words eventually developed into the English “full” and “fill” along with their equivalents in German, Dutch, Swedish, Danish, Icelandic, and Norwegian.
But the story goes back even beyond the early Germanic languages, which are only one branch of the Indo-European family tree.
The ultimate source, as Ayto notes, is an Indo-European root reconstructed as ple-.
This root, according to The American Heritage Dictionary of Indo-European Roots, by Calvert Watkins, has given us “derivatives referring to abundance and multitude.”
The ple- root has descendants not only in the Germanic languages—in which the “p” sound became “f”—but also in Latin and Greek.
English inherited words having to do with abundance and multitude from both directions.
From the Germanic direction, in addition to “full” and “fill,” English has the word “folk” (people), from the prehistoric Germanic word folkam.
On the classical side, the ple- root is the source of the Latin words plenus (full), plere (to fill) and plus (more), as well as the Greek polus (many), pleres (full), plethein (to be full), and pleon (more).
And from this direction, according to Watkins, English acquired “plenary,” “plenitude,” “plenty,” “replenish,” “plural,” “plus,” “nonplus,” “pluperfect,” “surplus,” “hoi polloi,” “plebian,” “plethora,” “accomplish,” “complement,” “complete,” “compliment,” “comply, “deplete,” “expletive,” “implement,” “replete,” “supply,” and the prefix “poly-,” among others.
In case you’re curious about “fulfill,” etymologically it means to “fill full” though that sense of the word is now defunct.
The OED says that when “fulfill” entered Old English as fullfyllan more than a thousand years ago, it meant “to fill to the full, fill up, make full.”
In case you haven’t had your fill yet, we had a brief post back in 2007 about whether to use the word element “full” or “ful” as a prefix or a suffix.
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