おば
おば
noun
aunt
1.
aunt
One's parent's sister, or the wife of one's parent's sibling.
When written in kanji, there are two forms: 伯母 for an aunt older than your parent, and 叔母 for an aunt younger than your parent. In casual writing, おば is often written in hiragana. When referring to someone else's aunt politely, use おばさん.
Note: おばさん can also be used generally for middle-aged women.