Callow means “lacking adult sophistication.” Often used to describe a young person who does not have much experience and does not know how to behave like an adult. Callow comes from calu, a word that meant "bald" in Middle English and Old English. By the 17th century, callow had come to mean "without feathers" and was applied to young birds not yet ready for flight. The term was also used for those who hadn't yet spread their wings in a figurative sense.