The most common and most likely answer to this crossword clue is the 4 plus 6 letter word LOOK SNAPPY
I've seen this crossword clue in The Guardian
L
O
O
K
S
N
A
P
P
Y
More clues leading to the result LOOK SNAPPY
- Hurry up — seems diaper is needed here
- Don’t drag feet bearing cross
- Hurry down to feed plant — can start in kitchen first
- Get your glad rags on — and your skates
- Be quick to appear fashionable
- Quickly appear fashionable
- Seems towelling filled with poo, shake a leg!
- Hasten to achieve a fashionable appearance?
Buddy explains!
The straight part
We know that "shake a leg!" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case shake a leg! = look snappy.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.