What is the meaning of Ə?

a reduced mid-central vowel, undefined for rounding.

[ə]-coloring or a weak, fleeting, epenthetic or echo [ə].

a reduced e vowel.

an extremely short or fleeting ə.

schwa, e.g. \sō′fə\ for sofa.

The seventh letter of the Azerbaijani alphabet, written in the Latin script.

A letter of the Comox alphabet, written in the Latin script.

A letter of the Fe'fe' alphabet, written in the Latin script.

A letter of the Halkomelem alphabet.

A letter of the Kwak'wala alphabet, written in the Latin script.

The eleventh letter of the Lushootseed alphabet.

The letter of the Maskelynes alphabet, written in the Latin script.

A letter of the Okanagan alphabet. ə́ counts as a distinct letter.

A letter of the Osage Latin alphabet. Osage script 𐓛.

Phonetic transcription of sounds [ə́, ə̀].

A letter of the Wakhi alphabet, written in the Latin script.

A letter of the Uyghur New Script of China

Source: wiktionary.org