A gear wheel.
Something behaving in a jerky manner similar to a a cogwheel, e.g. cogwheel respiration as a side effect of hyperbaric medicine.
A toothed wheel that enmeshes with a chain or other perforated band.
The tooth of such a wheel.
A placeholder name for an unnamed, unspecified, or hypothetical manufactured good or product.
A flared extension at the base of a sloped roof.