Body

KNUCKLE

A knuckle is a joint of a finger, especially the rounded prominence where the fingers meet the hand. The popping sound when cracking knuckles comes from gas bubbles bursting in the joint fluid. Contrary to popular belief, cracking them does not cause arthritis.

KNUCKLE is the kind of word that shows up in themed word searches like Strands. Themed puzzles group words like this under a shared category — here, Body.