1. A supplementary component that improves capability; such as, an optional part that may be fitted to something to perform an additional function or to enhance a performance.
2. Clothing that is worn or carried, but not part of a person's main clothing.
3. Someone who helps another person in committing a crime or avoiding arrest but who does not participate in the crime itself.

1. A reference to having a secondary, a supplementary, or a subordinate function.
2. Relating to something that is added but is not necessary.

The descending intercepting trunk for the upper, often the fourth through the eighth, left posterior intercostal veins: The accessory hemiazygos vein lies on the left side, and at the eighth thoracic vertebra it joins the hemiazygos vein, or crosses to the right side to join the azygos vein directly.

One of two masses of gray matter lying adjacent to the inferior olive of the brain.

A pigment found in plants, algae, and some bacteria, that absorbs light energy and channels it to the principal active pigment responsible for photosynthesis, usually a type of chlorophyll.

One of the small globular masses of splenic tissue occasionally found in the region of the spleen, in one of the peritoneal folds or elsewhere.