schwa

A mid-central neutral vowel, typically occurring in unstressed syllables, as the final vowel of English sofa.

The symbol (ə) used to represent an unstressed neutral vowel and, in some systems of phonetic transcription, a stressed mid-central vowel, as in but.

An indeterminate central vowel sound as the “a” in “about”, represented as /ə/ in IPA and /@/ in SAMPA and X-SAMPA.

The character ə, an upside-down, backwards, lower-case E

a neutral middle vowel; occurs in unstressed syllables