Nana is a term used to refer to a grandmother, and there are several variations of the word. A NURSE is a person who provides medical care, and the word can be abbreviated to 5 letters. GRAM is another word for grandmother, and it can be abbreviated to 4 letters. GRAMMA is a variation of the word GRAM, and it can be abbreviated to 6 letters. Grandma is another variation of the word GRAM, and it can be abbreviated to 7 letters. GRAN is a shortened version of the word grandmother, and it can be abbreviated to 4 letters. Finally, gan is a variation of the word grandmother, and it can be abbreviated to 3 letters.