• 糸いと — thread
• 毛糸けいと — wool yarn
• 糸口いとぐち — clue; beginning of a thread
• 糸電話いとでんわ — string telephone
• 絹糸けんし — silk thread
• 縫ぬい糸いと — sewing thread

“糸” originated as a pictograph of twisted thread. It appears in countless compound kanji and vocabulary related to weaving, sewing, and continuity. It also serves metaphorically in phrases like 糸口 (lead/clue) or 愛の糸 (threads of love).

糸いとでボタンぼたんを付つけました。
I sewed on the button with thread.

糸いとが切きれた。
The thread broke.