a movement back from an impact
"The heavy door slammed shut, causing the hinges to recoil in a sudden backlash of metal against wood."
an adverse reaction to some political or social occurrence
"there was a backlash of intolerance"
A sudden backward motion.
"The surfer was thrown off balance by a sharp backlash of water from the crashing wave."
To cause or set off a backlash.
"The company's decision to cut employee benefits immediately caused a massive backlash among its staff."
Backlash comes from combining the words back and lash. It originally meant to strike or whip backward.