The most common and most likely answer to this crossword clue is the 8 letter word GRANDSON
I've seen this crossword clue in The Guardian
G
R
A
N
D
S
O
N
More clues leading to the result GRANDSON
- Generous sum initially spent on young relative
- Family member making the sound of a big star
- Good African currency’s ready for younger relative
- Thousands working for a relative
- Thousands working for relative
- One among 25 pianos in performance
- Some pianos being played for young relative
- Fourth character encountered in “A Dance with Dragons” disturbed younger relative
- Scrummaging Dragon’s national successor
- One issue of offspring
Buddy explains!

The straight part
We know that "A boy’s boy?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a boy’s boy? = grandson.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 GRANDSON mean?
GRANDSON noun- A son of one's child.