Which prefix means self?

• A. somn/o
• B. later/o
• C. dermat/o
• D. aut/o

Answer: (D)

Self is expressed by aut/o, from the Greek autos meaning self. This combining form shows up in terms like automatic, autonomy, and autobiography, all illustrating the idea of self or self-directed action. The other forms have different meanings: somn/o relates to sleep, dermat/o to the skin, and later/o to the side or toward the side. So aut/o is the prefix that means self.