In snooker, a shot that leaves the cue ball touching an object ball is called a touching ball.
When the cue ball is touching a ball that could legally be played, the referee announces “touching ball.” The striker then does not have to move that object ball immediately; instead, the cue ball can be played away from it. The touching object ball must not be driven forward by the cue ball, because that would count as a push or an illegal contact.
The rule prevents a player from being penalised merely because the cue ball has come to rest against another ball. The striker still has to make a legal shot and must comply with the current ball-on requirement. If the touching ball is not on, the player normally must play away without first contacting it.
“Touching ball” is a technical snooker term, not simply a description of a frozen position. It is also distinct from a ball being close to another ball without actual contact.