A small circle used on the inputs to a logic gate symbol to indicate an active-low input or control, or on the outputs to indicate a negation (inversion) or a complementary signal. Some engineers prefer to use the term bubble.
A bad step away from the starting gate, sometimes caused by the ground breaking away from under a horse and causing him to duck his head or go to his knees.
A bad step away from the starting gate, usually caused by the track surface breaking away from under a horse's hooves, causing it to duck its head or nearly go to his knees.
In knitting, a bobble is a localized set of stitches forming a raised bump. The bumps are usually arranged in a regular geometrical pattern (e.g., a hexagonal grid) or may be figurative, e.g., represent apples on a knitted tree.