The most common and most likely answer to this crossword clue is the 8 letter word SILENTLY
I've seen this crossword clue in The Daily Telegraph
S
I
L
E
N
T
L
Y
More clues leading to the result SILENTLY
- Without speaking trash, left in style
- Knowing to hold one fast without making a sound
- Cunning, keeping one period of abstinence without talking
- . Foolish to have left in wife’s absence without making any noise
- Listen properly to lady's tips without making any noise
- Fool embraces Fangorn tree without a word
Buddy explains!

The straight part
We know that "without talking" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case without talking = silently.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 SILENTLY mean?
SILENTLY adverb- In a silent manner; making no noise.