The most common and most likely answer to this crossword clue is the 8 letter word DISSOLVE
I've seen this crossword clue in Financial Times
D
I
S
S
O
L
V
E
More clues leading to the result DISSOLVE
- Wind up using underworld crack
- Sid’s love unfortunately is to disappear
- To break with boyfriend ultimately is what you're aiming to do
- Wind up girl, only about five
- Collapse emotionally seconds after girl gets to explain
- End rise of deficit in drop
- Nullify and criticise what you do
- Break up with plunge over reflected failure
- Wind up, seeing deficit reversed in seedy club!
- Finish with detectives only claiming victory
Buddy explains!

The straight part
We know that "Nullify" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case nullify = dissolve.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 DISSOLVE mean?
DISSOLVE noun- A form of film punctuation in which there is a gradual transition from one scene to the next
- To terminate a union of multiple members actively, as by disbanding.
- To destroy, make disappear.
- To liquify, melt into a fluid.
- To be melted, changed into a fluid.
- To disintegrate chemically into a solution by immersion into a liquid or gas.
- To be disintegrated by such immersion.
- To disperse, drive apart a group of persons.
- To break the continuity of; to disconnect; to loosen; to undo; to separate.
- To annul; to rescind; to discharge or release.
- To shift from one shot to another by having the former fade out as the latter fades in.
- To resolve itself as by dissolution.
- To solve; to clear up; to resolve.
- To relax by pleasure; to make powerless.