(British) Elasticated band used for securing hair (for instance in a ponytail), a hair tie
(informal) A pill (ball formed on surface of fabric, as on laundered clothes).
(knitting) A localized set of stitches forming a raised bump.
2008, Claire Compton, ‎Sue Whiting, The Knitting and Crochet Bible (page 45)From the top the sample shows four stitch popcorns, five stitch bobbles, two rows of bells and a central leaf with leaves sloping to the left and right each side.
November 17 2012, BBC Sport: Arsenal 5-2 Tottenhamhttp://www.bbc.co.uk/sport/0/football/20278355A neat interchange between Mikel Arteta and Wilshere set up Podolski and his finish bobbled into the net via Gallas.