Definition of "schwa"

schwa¹

/ʃwɑ/

noun
plural schwas
1. (phonetics) An indeterminate central vowel sound as the "a" in "about", represented as /ə/ in IPA.
  Quotations
  The participle has also, owing to the accent, the lightest possible forms; but here there was no reduplication, and so in class I. the "schwa" took the form e before single mutes or fricatives, and elsewhere o.
  1882, B. W. Wells, “The Ablaut in English”, in Transactions of the American Philological Association, page 67
  However, word-final unstressed schwa is deleted even by the speakers from South Albania, though to different degrees and dependant on the speech style […]
  2006 April 27, Sylvia Moosmüller, Theodor Granser, “The spread of Standard Albanian: An illustration based on an analysis of vowels”, in Language Variation and Change, volume 18, number 2, Cambridge University Press
2. The character ə.
verb
third-person singular simple present schwas, present participle schwaing, simple past and past participle schwaed
1. (phonetics, of a vowel sound, rare) To be reduced to schwa.