What is the meaning of ä?

Sometimes used to transcribe an open central unrounded vowel, as a is officially an open front vowel.

Annuity-due.

A dictionary transcription for the PALM vowel

I (first-person singular subjective)

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

island

The third letter of the Livonian alphabet, written in the Latin script.

The thirty-sixth letter of the Skolt Sami alphabet, written in the Latin script.

The second letter of the Resian alphabet, written in the Latin script.

A letter of the Southern Tutchone alphabet, written in the Latin script.

axe

The twenty-eighth letter of the Estonian alphabet, called ää and written in the Latin script.

The twenty-seventh letter of the Finnish alphabet, called ää and written in the Latin script.

Alternative form of Ä

Used to represent a dialectal centralized vowel.

The third letter of the Slovak alphabet, written in the Latin script.

The second last letter of the Swedish alphabet, pronounced /ɛː/ when long, /ɛ/ when short, /æː/ when long and before r, and /æ/ when short and before r.

The sixth letter of the Turkmen alphabet, called ä and written in the Latin script.

Verbal prefix for the imperfect tense.

The letter A, marked for its syllabic pronunciation distinct from adjacent vowels.

Source: wiktionary.org