Pronunciation: (bak'lash"),[key] —n. 1. a sudden, forceful backward movement; recoil.
2. a strong or violent reaction, as to some social or political change: a backlash of angry feeling among Southern conservatives within the party. 3. Mach. a. the space between the thickness of a gear tooth and the width of the space between teeth in the mating gear, designed to allow for a film of lubricant, binding from heat expansion and eccentricity, or manufacturing inaccuracies.
b. play or lost motion between loosely fitting machine parts.
4. Angling.a snarled line on a reel, usually caused by a faulty cast.