Cop- Name for the yarn wound onto your spindle.
Crimp- Texture of your fiber. Like human hair, sheep fleece can be curly, wavy, or almost straight.
Half hitch- Type of loop used to keep your yarn secured to the shaft of your spindle.
Leader- yarn used to start a spinning project. You can either use a scrap of yarn, or roll roving on your thigh so it is strong enough to support the weight of the spindle.
Plied- Two or more strands of yarn that have been twisted together in the opposite direction.
Roving- Cleaned and carded fiber that is ready to spin.
S Twist- Yarn spun to the left.
Single- A yarn that is a single strand.
Staple length- Length of the individual fibers in your roving. Merino wool has a short fiber staple, whereas a Wensleydale fleece has fibers that can be a foot long.
Supported spindle- A type of spindle that spins on a surface, like a cup, bowl, table, or the ground. This works particularly well for fine, short-stapled fibers such as cashmere or cotton.
Suspended spindle- A spindle that spins in the air, and held up by spun yarn attached to your fiber supply. Also called a drop spindle.
Whorl- A spindle’s whorl can be at the top, bottom, or in the middle of the shaft. The placement of the whorl can effect the spin of your spindle.
Wraps per Inch (WPI)- A way to measure the diameter of handspun yarn without knitting a swatch. Wrap your yarn around a WPI tool or a ruler, and measure how many times you can wrap your yarn in a one inch increment.
Here is a chart to how WPI corresponds with yarn weights.
Z Twist- Yarn spun to the right.