Stefano Marchionini afterthought af⋅ter⋅thought [af-ter-thawt] –noun 1. a later or second thought; reconsideration. 2. reflection after an act; an appropriate explanation, answer, expedient, or the like, conceived of too late for the occasion. 3. something added, as a part or feature, that was not included in the original plan or design: The vestry was added to the church as an afterthought. a home a b c d e f g h i j k l m n o p q r s t u v w x y z abandon abundance absence advertisement access ache afterthought airport air-vent afro album alien all-art