The letter zeta represented the
affricate DZ in the original
Greek alphabet, which had apparently changed to ZD in classical (
Periclean) times, in most dialects, but it later changed to the simple Z sound of today.
When the Romans borrowed Greek words, at first they used their own S to represent the sound, but later, once they took on more Greek, they adopted the Greek zeta.
The Etruscans having had no use for the sixth letter, it was dropped from the Etruscan alphabet, which the Romans adopted. So when they re-imported it they put it at the end.
In Latin poetry it makes a preceding syllable "long", which indicates it had a double articulation: presumably ZZ, an intermediate stage between earlier Greek DZ or ZD and later Z. However, the fact that earlier borrowings used S mean that they were likely to have been taken from a variety of Greek where it had already changed to Z. This was after the height of the Classical Greek period, in which it was ZD in Athens, but only a century or so after.
The zeta arose from a number of sources in pre-Greek.
- It came from an earlier consonantal Y sound, cf. Greek zugon with Latin iugum and English yoke, all related and meaning the same.
- It came from DY, as in Zeus compared with deus and Tiw, the god whose name lives in Tuesday.
- It came from GY, as in meizon 'bigger', cf. the familiar mega- 'big'.
- It came from GWY.
- It came from SD, pronounced ZD, as in nizos related to and meaning 'nest' (both originally *nisdos in Proto-Indo-European).
The first four changes must have proceeded via an
intermediate sound like an English J. Compare the Latin
iugum, which did indeed acquire this sound around 500, as in 'sub-jug-ate'.
The fifth is a common process known as metathesis, the interchange of consonants as in 'ask' and 'aks'. So ZD became DZ. Either that, or ZD stayed ZD in words like nisdos, and the letter zeta (original value DZ) was used for ZD also, at the same time. I question the likelihood of this.
At some point the J sound became DZ. This was possibly before the adoption of the alphabet, since all the origins are represented by the same letter zeta even in the oldest texts. And it is extremely unlikely that a letter J was also used for ZD in nisdos.
Here's what I said at this point when I first noded this:
DZ is a phonologically natural single sound, just like J. It is natural to use a single letter for DZ if your language contains it. It is most odd to devise a letter for ZD, which is just a cluster of consonants. Yet even otherwise intelligent books on Greek persist in stating that zeta was pronounced ZD. Quite obviously, when Z and D happened to come together in a word, some speakers metathesized them to DZ, and if they did, they wrote it with zeta. For other speakers it remained Z-D and they wrote it sigma-delta. This is why you get both spellings alternating.
If you said 'ask' rather than 'aks', you wouldn't spell it 'ax', would you? You'd only spell it 'ax' if that's how you said it.
I now have to retract that, at least partly, since acquiring the best book on Greek pronunciation,
Vox Graeca by W. Sidney Allen. (The same author's companion volume
Vox Latina is equally invaluable.) I reluctantly concede that zeta was ZD, at least
medially, in
Attic, that is Classical Greek. The
metathesis of DZ to ZD must have been one-sided enough that it was always ZD by then, since that's what classical grammarians describe it as, and it behaves like a
sibilant after some prefixes where this makes a difference.
I have updated this node to be more cautious about the value, though the Latin borrowing evidence is puzzling, as Latin could easily have written sd, as it did with sb as in Lesbos, which uncontroversially we know was pronounced ZB.
However, the evidence for it being ZD in initial position seems to be close to zero; one obscure pun, and the lack of mention by ancient grammarians that it had a different sound initially. Vox Graeca doesn't mention any alternative spellings with sigma-delta. Was Zeus ever written Sdeus; did they ever write sdeugma?
The argument from the behaviour of the prefix syn- is weak. This had the form syn- before the stop D, and the form sy- before the sibilant S. So the fact that it was sy- before zeta is said to imply that zeta began with a sibilant. But if we accept that it was ZD medially, the prefix creates a medial environment, and says nothing significant about the initial value.
A medial metathesis of DZ to ZD I can accept (those are my teeth you can hear gritting), but I still find it highly implausible that this happened initially too, so I'm going to stick with DZ there. Harumph.
This alternation does definitely appear to have happened in the Lesbian dialect, which consistently writes σδ within a word but ζ initially. When a prefix is added to a zeta-initial word the zeta is replaced by sigma delta.
Greek letters were used, with a stroke, as numerals. Zeta was sixth in Greek but seventh in the Semitic alphabets, the letter digamma (a W sound) having been lost in Greek. But the old letter was retained for the numeric value 6, so ζ' meant 7.
The name is a puzzle. The Hebrew is zayin; the Phoenician would have been similar. The names of the Greek sibilants seem to have got a bit mixed up, and the name ζητα might derive from a different Semitic letter, sade.
For the time being I can't think of anything else to say about zeta.