Definitions
1.nounA sudden backward motion.
2.nounA negative reaction, objection or outcry, especially of a violent or abrupt nature."The public backlash to the proposal was quick and insistent."
3.nounThe 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.
4.nounThe jarring or reflex motion caused in badly fitting machinery by irregularities in velocity or a reverse of motion.
5.verbTo cause or set off a backlash.