How do you say cousin in yiddish?

The Yiddish word for cousin is "אחי" (akhi) for a male cousin and "אחותי" (achoti) for a female cousin.

However, it's important to note that these words also mean "brother" and "sister" in Yiddish. To specify that you're talking about a cousin, you would typically use a phrase like "אחי / אחותי פון מיין טאטע / מאמע" (akhi/achoti fun mein tate/mame), which means "brother/sister from my father/mother."