The most common and most likely answer to this crossword clue is the 7 letter word GRANDMA
I've seen this crossword clue in Independent
G
R
A
N
D
M
A
More clues leading to the result GRANDMA
- Relative giving graduate £1,000 for a start
- South African ready to visit on vacation glum adult family member
- Nanny imposing end to extra pocket money
- Old lady needs a lot of money to graduate
- Drag man out to see aged parent
- Nan with marg spread over it
- Moses’s nickname, given by fine old woman
- Relative borders of Greater Mesopotamia
- King George with his mother and her mother
- First-class degree for relative
Buddy explains!

The straight part
We know that "Nan" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case nan = grandma.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does GRANDMA mean?
GRANDMA noun- Grandmother