The most common and most likely answer to this crossword clue is the 4 letter word TURN
I've seen this crossword clue in The Times
T
U
R
N
More clues leading to the result TURN
- Change one’s act?
- Performer rejected new routine
- Change routine
- I must be ousted from Italian city in revolution
- Starts to tense up, restless, nearing junction
- English painter dismissing the Queen’s circle
- Surprise performance
- Change stage act
- Leaving Italian city, I change direction
- Change of direction is a shock
Buddy explains!

The straight part
We know that "Change of direction/shock" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case change of direction/shock = turn.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 TURN mean?
TURN verb- (heading) to make a non-linear physical movement.
- (heading) To change condition or attitude.
- To change one's course of action; to take a new approach.
- (usually with over) To complete.
- To make (money); turn a profit.
- Of a player, to go past an opposition player with the ball in one's control.
- To undergo the process of turning on a lathe.
- To bring down the feet of a child in the womb, in order to facilitate delivery.
- To invert a type of the same thickness, as a temporary substitute for any sort which is exhausted.
- To translate.
- To magically or divinely attack undead.
- A change of direction or orientation.
- A movement of an object about its own axis in one direction that continues until the object returns to its initial orientation.
- A walk to and fro.
- A chance to use (something) shared in sequence with others.
- A spell of work, especially the time allotted to a person in a rota or schedule.
- One's chance to make a move in a game having two or more players.
- A figure in music, often denoted ~, consisting of the note above the one indicated, the note itself, the note below the one indicated, and the note itself again.
- The time required to complete a project.
- A fit or a period of giddiness.
- A change in temperament or circumstance.
- A sideways movement of the ball when it bounces (caused by rotation in flight).
- The fourth communal card in Texas hold 'em.
- The flop (the first three community cards) in Texas hold 'em.
- A deed done to another; an act of kindness or malice.
- A single loop of a coil.
- (rope) A pass behind or through an object.
- Character; personality; nature.
- An instance of going past an opposition player with the ball in one's control.
- (circus, especially physical comedy) A short skit, act, or routine.
- A type turned upside down to serve for another character that is not available.
- The profit made by a stockjobber, being the difference between the buying and selling prices.