The crossword solution for the term FOLLOWER DUCT is TAPE, which is a four-letter word. TAPE is a type of adhesive material that is used to stick two surfaces together. It is commonly used in a variety of applications, such as sealing packages, attaching labels, and repairing items. TAPE is also used to create a follower duct, which is a type of air duct that is designed to follow the contours of a building's walls and ceilings.