bobble

Short definition from Wiktionary

Noun

1. 1
   A furry ball attached on top of a hat.
2. 2
   Elasticated band used for securing hair (for instance in a ponytail), a hair tie
3. 3
   A pill (a ball formed on the surface of the fabric, as on laundered clothes).
4. 4
   A localized set of stitches forming a raised bump.
5. 5
   A wobbling motion.

Verb

1. 1
   To bob up and down.
2. 2
   To make a mistake in.
3. 3
   To roll slowly.
4. 4
   To mishandle a ball.
5. 5
   To use the bobble stitch.