The most common and most likely answer to this crossword clue is the 6 letter word CARROT
I've seen this crossword clue in Independent
C
A
R
R
O
T
More clues leading to the result CARROT
- Orange or rust?
- Reason for an MOT failure?
- Sign of something extra, or amount of gold, announced as incentive
- Incentive for a bishop in bed
- Incentive to get back into motor racing
- Incentive – to visit a mechanic?
- Corbyn’s just started a right load of malarkey as an “inducement”
- Incentive for panel game host to do send-up
- Before crumble, perhaps banger and veg
- Incentive for vehicle to get up hill
Buddy explains!

The straight part
We know that "Incentive" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case incentive = carrot.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 CARROT mean?
CARROT noun- A vegetable with a nutritious, juicy, sweet root that is often orange in colour, Daucus carota, especially the subspecies sativus in the family Apiaceae.
- A shade of orange similar to the flesh of most carrots (also called carrot orange).
- Any motivational tool.
- To treat (an animal pelt) with a solution of mercuric nitrate as part of felt manufacture.