Mangai in Tamil language means "Green Mango" or "Unripe" Mango.
"Maa" in Tamil language is Mango and "Kai" (as you could note in the ingredients page) means vegetable.
Hence Mangai refers to vegetable used for making main and side dishes.
A Single green mango
This is one of the traditional vegetable of Tamils.
However, it is most famous for fruit form, Mango.
Mangai is considered to have high medicinal values. Country side people eat Mangai often and many homes will have a Mango tree.
Pregnant women eat this green mango as it has sour taste which reduces the vomitting sensation.
Mangai in cut form for main dish:
Green mango in cut form is used to Sambar or Kuzhambu as main vegetable. Some times It is added in fish kuzhambu to give an additional sour taste which makes fish kuzhambu tastes much better.
Mangai in cut form for side dish: Green mango in cut form is used to make a side dish called, patchadi. Mango patchadi is a very delicious side dish as it has the sweet, sour and savory taste.
Spelling variations in Tamil name for Green Mango:
Mankai, Maangai, Maankai, Maan gai