Thread eye refers to the small opening in a needle through which a thread is passed. Some synonyms for this term include needle eye, sewing eye, and stitching eye. The word threader is also sometimes used to describe tools or devices used to thread needles. Other related terms include hook eye, fishing eye, and beading eye, which refer to the openings in fishing hooks and beads that are used for threading. Whatever term is used, the thread eye is an important part of any sewing or crafting project, allowing threads and yarns to be passed through small spaces and creating intricate designs and patterns.