The term SMART ONE can be broken down into five crossword solutions: BRAIN (5 letters), ALEC (4 letters), SASSER (6 letters), ALECK (5 letters), and MENSAN (6 letters). BRAIN is a common term used to refer to the organ in the human body that is responsible for thought, memory, emotion, and other cognitive functions. ALEC is a shortened form of the name Alexander, which is derived from the Greek word meaning 'defender of mankind'. SASSER is an acronym for System Administration, Security, and Service Emergency Response, which is a type of computer security system. ALECK is a variant spelling of ALEC, and MENSAN is a term used to describe someone who has achieved a high score on an IQ test.