Even if you don't know the word schwa you've likely seen one. It's the inverted letter "e" used to represent neutral the vowel sound in generally weakly stressed syllables. Examples include the "i" in pencil or the "u" in circus. The word schwa comes to us from Hebrew via German. In Rabbinic Hebrew, schwa (שְׁוָא) literally means "emptiness" or "vanity". For you folks in the audience who had to suffer through years of Hebrew school I guarantee you encountered the schwa fairly regularly: Remember those dots that appeared under the Hebrew letters that signified the vowel sounds? Well, they are collectively called "niqqud marks" and schwa originally referred to the vowel that looks like a vertical pair of dots, :. The Hebrew word itself likely comes from the Syriac šwayyā, meaning "even", which I'm guessing describes the identical nature of the two points.

Today, however, the : vowel mark is more commonly called a sheva in English in order to differentiate it from Ə. Sheva is simply an arbitrarily constructed alteration of schwa.

schwa [Wikipedia]
niqqud [Wikipedia]
schwa [AHD]
sheva [OED]

Labels: Hebrew, Syriac, The Daily Hump