The most common and most likely answer to this crossword clue is the 2 plus 4 letter word AT ONCE
I've seen this crossword clue in The Guardian
A
T
O
N
C
E
More clues leading to the result AT ONCE
- With expert circling, “abrupt” Blair’s on the spot
- This second hundred comes in one
- Expert bearing weight right away
- Expert pockets a hundred immediately
- 14 is wearing make up right now
- . Agreed about copyright straight away
- In agreement over Conservative leader right away
- Expert grips weight immediately
- Catching cold, remedy immediately
- Having let cold in, make amends immediately
Buddy explains!
The straight part
We know that "Now" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case now = at once.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.