1. something that is thought of or added later, often as less important
2. a thought that occurs to someone later

Examples

• The garage was built as an afterthought to the original house plans.
• She added the decorations as an afterthought before the party.
• His apology seemed like an afterthought rather than genuine remorse.
• The safety features were clearly an afterthought in the design process.
• As an afterthought, she decided to bring extra snacks.
• The children often felt like afterthoughts in their parents’ busy lives.
• He mentioned the meeting time as an afterthought at the end of his email.