In Yiddish, it's often used as a term of endearment for a young girl or woman. It can also be used as a playful or affectionate nickname, similar to how we might use "sweetheart" or "honey" in English.
It's important to note that the word "Feigele" itself doesn't have a direct translation into English. The closest equivalent would be a term like "little fig" or "dear one," but it carries a specific connotation of affection and warmth in Yiddish.