The term SMART ___ (WISE GUY) can be filled in with three different words: ALECK (5 letters), ASS (3 letters), and ALEC (4 letters). ALECK is a variant of the name Alexander, which is derived from the Greek word for 'defender of men'. ASS is an informal term for a donkey, which is an animal known for its intelligence and loyalty. ALEC is a variant of the name Alexander, and is also derived from the Greek word for 'defender of men'. All three words can be used to describe someone who is wise and intelligent.