How do say uncle in Hindi language?

The word for "uncle" in Hindi depends on the specific relationship:

For your father's brother:

* Chacha (चाचा)

For your mother's brother:

* Mama (मामा)

For your father's sister's husband:

* Mama (मामा) or Fua (फुआ) (depending on the region)

For your mother's sister's husband:

* Mausi (मासी) or Fua (फुआ) (depending on the region)

For any elderly man you respect:

* Tau (ताऊ)

It's important to note that these are just the most common terms. There are many other ways to address an uncle in Hindi, depending on the specific relationship and the region.