Reserve for the future

• Rainy day reserve
• Something for a rainy day
• Rainy day resource
• You may use it after retiring
• Little something to help later on
• IRA, e.g
• Rainy-day provision
• Reserve money
• Money laid aside for some future eventuality

Wikipedia Word definitions in Wikipedia
NestEgg , is a line of egg-shaped chocolate candies made by Nestlé .