The most common and most likely answer to this crossword clue is the 4 plus 4 letter word BONA FIDE
I've seen this crossword clue in The Daily Telegraph
B
O
N
A
F
I
D
E
More clues leading to the result BONA FIDE
- Papers found by a fellow in Ilium, possibly authentic
- Fob Diane off for real?
- Fed boa in fragments? True! [two words]
- Sincere Latin
- Genuine Jedi fan objecting, upset to some extent
- Real beano arranged, to include daughter, if back
- A dog endlessly tucks into his favourite food? True!
- Bad, if one turns out to be genuine
- Genuine gift nothing less found by assistant touring France
- A tailless dog getting stuck into its food — for real
Buddy explains!

The straight part
We know that "genuine" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case genuine = bona fide.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.