The most common and most likely answer to this crossword clue is the 6 letter word RETYPE
I've seen this crossword clue in The Guardian
R
E
T
Y
P
E
More clues leading to the result RETYPE
- Passage in entirety periodically input again
- Key once more accessing sleepy terrace from the basement?
- Put in another class? Correct
- Sliding back, somewhat weepy, terrifying to get down again
- Religious Education class gets record again
- Regime seeing annihilation of middle class as key again
- Religious education class is key once more
- Engineers class again make an impression in print
- 60s motoring icon after right to produce copy?
- Produce new script about model
Buddy explains!

The straight part
We know that "Key once more" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case key once more = retype.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 RETYPE mean?
RETYPE verb- To re-enter (text) using a keyboard.