The most common and most likely answer to this crossword clue is the 4 letter word RISK
I've seen this crossword clue in Independent
R
I
S
K
More clues leading to the result RISK
- Chance taken to bring king and knight up
- Chance that meeting with bachelor might be quick
- Busy bee ignored hazard
- . Possibility that doctor is kissing nurses
- Quick to miss leader in uncertainty
- Uncertainty is keeping queen and king apart
- Danger of Queen covering one’s King
- Search force missing danger
- Take a chance on body-search with top off
- Danger — quick to remove bishop
Buddy explains!

The straight part
We know that "Uncertainty" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case uncertainty = risk.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 RISK mean?
RISK noun- A possible adverse event or outcome
- The probability of a negative outcome to a decision or event.
- The magnitude of possible loss consequent to a decision or event.
- (formal use in business, engineering, etc.) The potential (conventionally negative) effect of an event, determined by combining the likelihood of the event occurring with the effect should it occur.
- An entity insured by an insurer or the specific uncertain events that the insurer underwrites.
- To incur risk of (something).
- To incur risk of harming or jeopardizing.
- To incur risk as a result of (doing something).