The most common and most likely answer to this crossword clue is the 7 letter word GAINFUL
I've seen this crossword clue in Independent
G
A
I
N
F
U
L
More clues leading to the result GAINFUL
- Rewarding golf? Agonising missing first of putts
- Popular female visiting France no longer productive
- Productive government losing power, irritating
- Popular fellow entering France in past proves profitable
- Fail with gun reform? It can be rewarding
- Lucrative enough to provide some wonga in Fulham?
- Fungal infection’s beginning to spread, becoming lucrative
- Flying uni flag could be worthwhile
- Lingua Franca primarily used, it's productive
- Frenchman possesses brief news that is worthwhile
Buddy explains!

The straight part
We know that "profitable" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case profitable = gainful.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 GAINFUL mean?
GAINFUL adjective- Contrary.
- Disposed to taking advantage of.
- Troublesome; fractious; hard to handle.
- Providing gain; profitable.