KanjiJLPT N1
Fasten

fasten, tie up, arrest, constrict

Mnemonic

Your hand grabs a loose rope while your tongue clamps the other end between your teeth — together you fasten the bundle tight. You pull with your hand, bite down with your tongue, and fasten knot after knot until nothing can come undone.
Additional thoughts
Picture literally holding rope in one hand and biting it to keep tension — the coordination of hand and tongue is what makes fastening possible. The tongue inside the mouth mirrors the knot cinched inside the bundle.
Quick recall
Use your hand and tongue to fasten a tight knot by pulling and biting the rope.

Details

The keyword for 括 is fasten. This kanji conveys the idea of binding, tying together, or bundling things up securely. It carries the sense of gathering loose elements and securing them into a unified whole, much like tying a knot to keep things in place. By extension, it can also mean to summarize or bring things together into a cohesive conclusion.
On'yomi
かつ
Kun'yomi
くく.る