In Hindi, your younger brother’s wife is referred to as “भाभी” (Bhabhi). This term is commonly used to show respect and affection for your brother’s wife, regardless of whether he is younger or older. In some regions or families, if your brother is younger, people might specify “छोटी भाभी” (Chhoti Bhabhi), meaning “younger sister-in-law,” to distinguish her from the elder brother’s wife. However, “Bhabhi” alone is widely understood and appropriate. The relationship holds a cultural significance in Indian families, often involving a bond of mutual respect, playfulness, and care between the brother-in-law and the Bhabhi.