One of my favorite topics to write about is the change of meaning in words relating to food. We've already seen that a melafefon originally meant melon, now cucumber, and that botnim, while in modern Hebrew mean peanuts, meant pistachios in the Bible. However, these discussions, while interesting, don't have much practical impact. On the other hand, some debates have real halachic significance.
For example, in to Jewish law, there are five species of grain in the Land of Israel that have special laws relating to them - what blessing is made, can they be used to make matza (or do they constitute chametz), must one "separate challah" with bread made from them, and more. As described in the Mishna (Hallah 1:1), the five grains are:
החיטים, והשעורים, והכוסמין, ושיבולת שועל והשיפון
chitim, seorim, kusmin, shibolet shual, shifonChitim are wheat and seorim are barley. We'll discuss kusmin in a future post, but now I'd like to deal with shibolet shual and shifon (or shipon, more on that in a bit.) In modern Hebrew, shibolet shual means "oats" (although "kvaker" is the common term), and shifon means "rye". This goes as far back as Rashi, who identifies them as such in his commentary (Pesachim 35a). However, many modern scholars disagree with this approach, such as Immanuel Low, who writes that shibolet shual is millet, and shifon is oats (both Jastrow and Ben Yehuda mention this approach), and more recently Yehuda Feliks, who says that shibolet shual is "two-rowed barley" (compared to the four and six rowed barley for seorim) and shifon is spelt (which in modern Hebrew is kusmin). Feliks gives a number of reasons for his conclusions - primary among them is that oats and rye were not commonly grown in the Land of Israel at the time of the mishna (this post does a good job of summarizing his arguments and those that disagree with him, on the identity of shibolet shu'al).
Most of the proofs are based on biological or historical evidence - but I did find one etymological aspect: while many claim that the name "shibolet shual" comes the spike, shibolet, of plant looking like the tail of a fox, shual, (and we find the phrase "foxtail" with a similar meaning in English), Feliks believes that the name comes from the fact that foxes like eating the softer two-rowed barley more than other grains, in the same way that invei shual ענבי שועל - "blackcurrants" (literally "fox grapes") are so called because foxes enjoy eating them.
While the etymology might not help us understand the identity of shifon, it should help with the pronunciation. Looking at vocalized editions of the Mishna and Talmud, I see that they are pretty much split down the middle: Steinsaltz and Artscroll have shipon (or shippon in the English translation), whereas Kehati and Jastrow have shifon. Ben Yehuda writes that the correct pronunciation is shifon, because the word comes from Greek - siphonion, which seems to be related to the word siphon, meaning "tube, pipe", perhaps related to the shape of the plant. (Klein, following Ben-Yehuda writes that, "The attempt of [Immanuel] Low to derive shifon from שוף [= to polish] is far-fetched.) I've found references to siphonion both as oats (avena) and rye (secale), so I don't think this helps us identify the original plant.
However, Ben Yehuda goes on to complain that the popular pronunciation is shipon, and this is confirmed by Even Shoshan as well. The Hebrew Wikipedia article for שיפון says that it is pronounced shipon to distinguish it from the fabric "chiffon". However, from an (admittedly unscientific) poll I took of native Hebrew speakers - all of them pronounced the word shifon, and none had ever heard it pronounced shipon. While it is possible that a linguistic correction has taken place, I can't help wonder if they were all influenced by the popular bakery Shifon...