noun
A knot in a string, rope, or similar material; the point where something is tied.
靴ひもの結び目がほどけた。
The knot in my shoelace came undone.
ロープにしっかり結び目を作ってください。
Please make a firm knot in the rope.
Standard kanji spelling.
結ぶ is the verb 'to tie' or 'to connect'; 結び目 is the resulting knot.
Compound of 結び (musubi, 'tying', the continuative form of 結ぶ) and 目 (me, 'point' or 'mark'), literally 'tying point'.