Definition from Wiktionary, the free dictionary
Etymology 1 
icing (plural icings)
- A sweet glaze made primarily of sugar and often flavored, typically used for baked goods; frosting.
- (ice hockey) A minor violation of ice hockey rules, occurring when a player shoots the puck from his/her side of the red line so that it crosses the goal line on the opponent's side, and the next player to touch the puck is an opponent player other than the goalie. A team playing short-handed is not penalized for this.
- The process of forming a layer of ice on a surface.
sweet glaze used for baked goods
process of forming a layer of ice
Etymology 2 
From the verb to ice.
- Present participle of ice.