The term 'CERTAIN FLOCK MEMBER' can be solved by the crossword answer 'BIRD', which is a four letter word. A BIRD is a type of animal that belongs to the class Aves, which includes all species of feathered, winged, two-footed creatures. Birds are found in almost every habitat on Earth and are known for their ability to fly. They are also known for their social behavior, often forming flocks or colonies. Therefore, a certain flock member would refer to a specific BIRD within a flock.