The most common and most likely answer to this crossword clue is the 9 letter word LITERALLY
I've seen this crossword clue in Financial Times
L
I
T
E
R
A
L
L
Y
More clues leading to the result LITERALLY
- Best, but not the first, meeting, strictly speaking
- Having limited calories, get better? Exactly
- Really drunk, really drunk!
- Truly less extreme gathering
- Really on fire and really worried!
- Get better following diet strictly
- American measure facing supporter closely
- Really fired up congregation about end of service
- It’ll relay changes word for word
- With a bit of translation, I’ll relay broadcast word for word
Buddy explains!

The straight part
We know that "Truly" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case truly = literally.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 LITERALLY mean?
LITERALLY adverb- Word for word; not figuratively; not as an idiom or metaphor
- (degree, contranym) Used non-literally as an intensifier for figurative statements: virtually, so to speak (often considered incorrect; see usage notes)
- Used to intensify or dramatise non-figurative statements; tending towards a meaningless filler word in repeated use.
- Used as a generic downtoner: just, merely.