Bobble Stitch
a raised cluster of stitches worked into one stitch, used for bumpy, textured surface designs

Bobble stitch groups several incomplete double crochets into one stitch, then closes them together at the top so the cluster pops forward off the surface of the fabric. Unlike popcorn stitch, which uses complete stitches, a bobble is built from stitches left unfinished until the final pull-through joins them all at once.
There's no US/UK split on the name itself, but since bobbles are built from double crochets, remember that US "double crochet" (dc) is UK "treble crochet" (tr) when reading a UK-written pattern.
How to work it
- Yarn over and insert your hook into the stitch.
- Yarn over and pull up a loop, then yarn over and pull through 2 loops (leaving 2 loops on your hook). This is one incomplete double crochet.
- Repeat step 1 and 2 in the same stitch 4 more times (5 incomplete double crochets total, 6 loops on your hook including the original).
- Yarn over and pull through all 6 loops at once. That's one bobble.
When to use it
Use bobble stitch to add raised, textured accents to an otherwise flat fabric, such as a scattered bobble pattern across a blanket or a single row of bobbles along a cuff. Space bobbles a stitch or two apart so the fabric doesn't stiffen up under the added bulk.