The most common and most likely answer to this crossword clue is the 6 letter word DITHER
I've seen this crossword clue in The Times
D
I
T
H
E
R
More clues leading to the result DITHER
- Trench digger losing heart in agitated state
- Be indecisive, beginning to discuss the matter with her
- Faff about Rimbaud’s named successor
- Vacillate, disheartening a digger of trenches
- Doctor embraces one with the trembling condition
- Either go back one step at the outset, or wobble
- Hesitate to free up article trapped inside
- Be uncertain about turning up with it in the middle of Oldham
- Article covered in filth when bottom scrubbed in lather
- Stew in France, said to touch that woman
Buddy explains!

The straight part
We know that "Vacillate" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case vacillate = dither.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 DITHER mean?
DITHER noun- The state of being undecided.
- To tremble, shake, or shiver with cold.
- To be uncertain or unable to make a decision about doing something.
- To do something nervously.
- To render an approximation of (an image, etc.) by using dot patterns to approximate (the features of) colors not in the system palette.
- To intentionally add noise to a signal to randomize errors.