What is the meaning of ى?

Only written in the final position, transliterated ā. Called أَلِف مَقْصُورَة (ʔalif maqṣūra, limited, restricted alif) or أَلِف لَيِّنَة (ʔalif layyina, flexible alif). In the rare case of a rasm version of Quran, it is the yāʾ version.

used to form feminine adjectives

The twenty-eighth letter of the Kazakh in Arabic Script. It represents the Cyrillic letter Ы or І.

The thirty-fifth letter of the Malay alphabet, written in the Arabic script.

The thirtieth letter of the Uyghur alphabet.

Source: wiktionary.org