an idea, thought, or plan that was not originally intended but is thought of at a later time事后想法;事后添加的事物
She only asked me to her party as an afterthought.她原本没有请我去参加她的聚会,只是后来才想起来的。
The pillars seem to have been added to the entrance as an afterthought.这些柱子好像是完工后在入口处添加上去的。