The most common and most likely answer to this crossword clue is the 4 letter word ROCK
I've seen this crossword clue in The Guardian
R
O
C
K
More clues leading to the result ROCK
- Pitch sure to be covered in stones
- Reliable type of souvenir from Blackpool?
- Marciano to lose his footing and sway from side to side
- Diamond tip
- We hear Big Bird to be highly enjoyable
- Stonefish?
- Stone cut film
- Decrepit old thing fails to start music
- After my turns, knee’s beginning to wobble
- Lull to sleep with this music
Buddy explains!

The straight part
We know that "sway from side to side" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sway from side to side = rock.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 ROCK mean?
ROCK noun- A formation of minerals, specifically:
- A large hill or island having no vegetation.
- Something that is strong, stable, and dependable; a person who provides security or support to another.
- A lump or cube of ice.
- A type of confectionery made from sugar in the shape of a stick, traditionally having some text running through its length.
- A crystallized lump of crack cocaine.
- An unintelligent person, especially one who repeats mistakes.
- An Afrikaner.
- An extremely conservative player who is willing to play only the very strongest hands.
- Any of several fish:
- A basketball.
- (rock paper scissors) A closed hand (a handshape resembling a rock), that beats scissors and loses to paper. It beats lizard and loses to Spock in rock-paper-scissors-lizard-Spock.
- A cricket ball, especially a new one that has not been softened by use
- A crystal used to control the radio frequency.
- An act of rocking; a rocking motion; a sway.
- To move gently back and forth.
- To cause to shake or sway violently.
- To sway or tilt violently back and forth.
- (of ore etc.) To be washed and panned in a cradle or in a rocker.
- To disturb the emotional equilibrium of; to distress; to greatly impact (most often positively).
- To do well or to be operating at high efficiency.
- To make love to or have sex with.
- A style of music characterized by basic drum-beat, generally 4/4 riffs, based on (usually electric) guitar, bass guitar, drums and vocals.
- To play, perform, or enjoy rock music, especially with a lot of skill or energy.
- To be very favourable or skilful; excel; be fantastic.
- To thrill or excite, especially with rock music
- To do something with excitement yet skillfully
- To wear (a piece of clothing, outfit etc.) successfully or with style; to carry off (a particular look, style).
- Distaff.
- The flax or wool on a distaff.
- An enormous mythical bird in Eastern legend.
- Rocuronium.