noun
embroidery thread
Refers to the thread used for embroidery. A straightforward compound of 刺繍 (embroidery) and 糸 (thread).
刺繍糸を買いに手芸店へ行った。
I went to a craft store to buy embroidery thread.
糸 is the general word for 'thread' or 'yarn'; 刺繍糸 is a specific type of thread used for embroidery.
Compound of 刺繍 (ししゅう, 'embroidery') and 糸 (いと, 'thread').