Erstwhile Indian currency unit, equal to 1/16th of a rupee. It was discontinued ten years after India gained independence, when the currency was decimalised.
Indian grandparents often mention it when talking about their carefree childhoods.
Not to be confused with Anna Hazare.
*Small kids in Shimla in 1940's India are walking home from school, and they pass P. Samuel's Sweet Shop*
Small kids : "Eeeeeeey P. Samuel, ek goli-toffee free mein de na. Please please please." (P.Samuel, give one goli-toffee for free na. Please please please)
P. Samuel : "Nothing doing! I can't give you sweets everyday for free. You'll get five if you give me one aanna."
Small kids set up loud chorus : "But we don't have one aana. Please please please please please please please please."