noun
binding thread; basting thread
Thread used for sewing book bindings or for temporary basting stitches in tailoring.
和綴じには綴じ糸が欠かせない。
Binding thread is essential for Japanese-style bookbinding.
仮縫いに綴じ糸を使う。
Use basting thread for temporary stitching.
Compound of 綴じ (とじ, continuative form of 綴じる 'to bind') + 糸 (いと 'thread').