Origin

The character 糸 is a picture of thread or silk fibers. The vertical strokes in the middle represent individual threads bundled together, while the horizontal lines at the top and bottom suggest how threads are twisted or bound. Over time, the shape simplified into the current form, but it still shows those parallel vertical lines that evoke the appearance of multiple thin strands. Because thread was so important in ancient East Asia for making cloth, this pictograph became the standard way to write the word for thread, and it's now used as a component in many other characters related to textiles and string.