back‧hand‧er /ˈbækhændə $ -ər/ 
 noun [countable]1.  a hit or shot that you do using the back of your hand
2.   British English informal money that you pay illegally and secretly to get something done
 Synonym : bribe: 
 Investigators estimate that £35m had been spent on bribes and backhanders.
 Investigators estimate that £35m had been spent on bribes and backhanders.  [TahlilGaran] Dictionary of Contemporary English ▲