The most common and most likely answer to this crossword clue is the 5 letter word FIXED
I've seen this crossword clue in The Daily Telegraph
F
I
X
E
D
More clues leading to the result FIXED
Buddy explains!

The straight part
We know that "Not likely to evaporate/fast" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case not likely to evaporate/fast = fixed.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 FIXED mean?
FIXED verb- To pierce; now generally replaced by transfix.
- To attach; to affix; to hold in place or at a particular time.
- To mend, to repair.
- To prepare (food or drink).
- To make (a contest, vote, or gamble) unfair; to privilege one contestant or a particular group of contestants, usually before the contest begins; to arrange immunity for defendants by tampering with the justice system via bribery or extortion
- To surgically render an animal, especially a pet, infertile.
- (sematics) To map a (point or subset) to itself.
- To take revenge on, to best; to serve justice on an assumed miscreant.
- To render (a photographic impression) permanent by treating with such applications as will make it insensitive to the action of light.
- To convert into a stable or available form.
- To become fixed; to settle or remain permanently; to cease from wandering; to rest.
- To become firm, so as to resist volatilization; to cease to flow or be fluid; to congeal; to become hard and malleable, as a metallic substance.
- Not changing, not able to be changed, staying the same.
- Stationary.
- Attached; affixed.
- Chemically stable.
- Supplied with what one needs.
- Of sound, recorded on a permanent medium.
- Surgically rendered infertile (spayed, neutered or castrated).
- Rigged; fraudulently prearranged.
- (of a problem) Resolved; corrected.
- Repaired