The most common and most likely answer to this crossword clue is the 6 letter word GENTLY
I've seen this crossword clue in Financial Times
G
E
N
T
L
Y
More clues leading to the result GENTLY
- You are to leave with dispatch, taking it easy
- Softly, with top priority, without hesitation!
- Man liberates your leaders gradually
- High-ranking people should change sides in a mild way
- Lords changing political allegiance gradually
- Man’s with woman losing heart gradually
- Mildly resembling a man?
- Gradually landowning class swaps sides
Buddy explains!

The straight part
We know that "gradually" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case gradually = gently.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 GENTLY mean?
GENTLY adverb- In a gentle manner