The most common and most likely answer to this crossword clue is the 4 plus 2 letter word KEEP UP
I've seen this crossword clue in The Daily Telegraph
K
E
E
P
U
P
More clues leading to the result KEEP UP
- Maintain part of castle in revolt
- Stay in contention with endlessly enthusiastic whippersnapper
- Stop going to bed and peek?
- Maintain important-sounding little dog?
- Maintain this could give you a sly look?
- Recipe for butcher’s preserve?
- Maintain competitive tailless dog
- Don’t lag, avoid grounding
- Continue paring sharp canine
- Maintain board’s winning
Buddy explains!
The straight part
We know that "Maintain" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case maintain = keep up.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.