A spindle is a stick or rod that spins, used for twisting fibers like wool or cotton into thread. For thousands of years before spinning wheels and factories existed, people made thread by hand using a simple wooden spindle. They'd attach loose fibers to the top, set the spindle spinning like a top, and as it twirled, the fibers would twist together into strong, usable thread. The spindle's weight and rotation did the work of turning fluffy wool into something you could weave into cloth.

You might recognize spindles from fairy tales: in Sleeping Beauty, the princess pricks her finger on a spinning wheel's spindle. Spinning wheels use a spindle too, just one that's part of a larger machine.

The word also describes anything long and thin that rotates or holds something while turning. The axle that connects a wheel to a car is sometimes called a spindle. A staircase with a central pole and steps wrapping around it has a spindle at its core. Biology teachers talk about spindles that appear in cells during division, pulling apart genetic material. The connecting idea: something slender and rod-like, often involved in turning or holding things in place while they rotate.