(anatomy) The system of osteons in compact bone

(physiology) The parts of an animal body comprising the heart, blood vessels (arteries, veins, and capillaries), and blood, which circulate the blood around the body.

A hierarchy of values that all moral beings have, reflected in their choices. Most people's value systems differ. It's an individualistic concept. One's value system is molded by one's virtues or vices, and experiences.

In Latin, the three perfect tenses: perfect, future perfect, and pluperfect or past perfect, as contrasted with the present system: present, future, and imperfect. A verb in the perfect system indicates an action that has completed.

In Latin, the three simple tenses: present, future, and imperfect, as contrasted with the perfect system, the three perfect tenses: perfect, future perfect, and pluperfect. Verbs in the present system tend to indicate an action that has not completed.

(medicine) A blood group system, the second most important after the ABO system, and important in human blood transfusion, whereby blood types are classified according to the presence ("positive") or absence ("negative") of potentially over 50 antigens, of which the most commonly referenced is RhD.

A pushchair with detachable carrycot or car seat.

A communication system in which multiple users share a common channel in a way that can lead to conflicts.

A system of beliefs.

A group of related components that are part of a larger system.