The most common and most likely answer to this crossword clue is the 7 letter word FERTILE
I've seen this crossword clue in The Daily Telegraph
F
E
R
T
I
L
E
More clues leading to the result FERTILE
- Loudly upset about term used in Scrabble? It's inventive
- Small body of soldiers storing last bits of the plunder set to be rich
- Rich cream that’s held back for dinner, fellow used up
- Fruitful time following Queen in procession
- After exchanging hands, experienced anger liable to multiply?
- Rich female about to return hat
Buddy explains!

The straight part
We know that "inventive" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case inventive = fertile.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 FERTILE mean?
FERTILE adjective- (of land etc) capable of growing abundant crops; productive
- Capable of reproducing; fecund, fruitful
- Capable of developing past the egg stage
- (of an imagination etc) productive or prolific