(arithmetic) A set of numerals for representing numbers.

(anatomy) In mammals, including humans, a network of lymph vessels and lymph nodes that transport fluid, fats, proteins, and lymphocytes to the bloodstream as lymph, and remove microorganisms and other debris from tissues.

(computing) A system allowing hardware and software from different manufacturers to be used together seamlessly. / (physics) A system that can exchange both matter and energy with its surroundings.

The practice of working or travelling together with at least one other person, especially when undertaking something potentially risky or hazardous.

An organ system that coordinates the activities of muscles, monitors organs, constructs and processes data received from the senses, and initiates actions.

The scientific analysis of systems, and the interactions within them.

(computing) A person whose job is to perform systems analysis by being responsible for researching, planning and recommending software and system choices to meet an organization's business requirements.

(anatomy, immunology) The system that differentiates self from non-self and protects the body from foreign substances and pathogenic organisms by producing an immune response. It includes organs such as the thymus, the spleen and lymph nodes; tissue such as bone marrow, and lymphoid tissues such as the tonsils; cells such as lymphocytes including the B cells and T cells, and cell products such as antibodies.

(astronomy) The combined system or structure formed by all of the rings orbiting a planet

(anatomy) A system of organs for the purpose of digesting food.