The distance through which one part of connected machinery, as a wheel, piston, or screw, can be moved without moving the connected parts, resulting from looseness in fitting or from wear; also, the jarring or reflex motion caused in badly fitting machinery by irregularities in velocity or a reverse of motion.
- A sudden or violent backward whipping motion.
- An antagonistic reaction to a trend, development, or event: "As the backlash against divorce progressed, state legislatures . . . called for a rollback of no-fault divorce laws and even for premarital waiting periods” ( Walter Kirn).
- A snarl formed in the part of a fishing line that is wound around the reel.
- The play resulting from loose connections between gears or other mechanical elements.