cinch in WordNet English dictionary

1. any undertaking that is easy to do
   "marketing this product will be no picnic"
   cinch  breeze  picnic  snap  duck soup  child's play  pushover  walkover  piece of cake 
   
2. a form of all fours in which the players bid for the privilege of naming trumps
   cinch 
   
3. stable gear consisting of a band around a horse's belly that holds the saddle in place
   cinch  girth 
   

1. get a grip on; get mastery of
   cinch 
   
2. make sure of
   cinch 
   
3. tie a cinch around
   "cinch horses"
   cinch  girth