Afterthought Second is a term used to describe something that is added after the main event or task has been completed. It is composed of three words: Afterthought, Second, AND ANNEX. Afterthought refers to something that is thought of after the fact, while Second is an ordinal number indicating position in a sequence. ANNEX is a noun meaning an addition or supplement. Together, these words form the phrase Afterthought Second ANNEX, which can be used to describe something that is added as an afterthought.