The most common and most likely answer to this crossword clue is the 6 letter word UNLESS
I've seen this crossword clue in The Guardian
U
N
L
E
S
S
More clues leading to the result UNLESS
- If not in the shade, removing top
- Except if overcast, going topless
- Save when banks leave fund a smaller amount
- In case large body gets smaller
- Cloudy? Sun’s come out if not
- But not if topless, without a tabloid
- If not overcast, taking top off
- Not melodic, lacking time, key and bar
- If not without cakes supposedly, the first polished off
- If not fun, when female’s gone there’s a smaller amount
Buddy explains!

The straight part
We know that "Save" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case save = unless.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 UNLESS mean?
UNLESS conjunction- Except on a specified condition; if not.
- If not; used with counterfactual conditionals.
- Except if; used with hypothetical conditionals.