neuroguy on dailykos, in an article that argues that Dr. Ben Carson is not smart, gives this description of smart that I want to preserve:
“Smart” is a multifaceted cognitive feature composed of excellent analytical skills, possession of an extensive knowledge base that is easily and frequently augmented, possession of a good memory, and being readily curious about the world and willing, even eager, to reject previously accepted notions in the face of new data. Being smart includes having the ability to analyze new data for validity and, thinking creatively, draw new insights from existing common knowledge.