sys·tem·ic / səˈstemik/ • adj. 1. of or relating to a system, esp. as opposed to a particular part: the disease is localized rather than systemic. ∎ (of an insecticide, fungicide, or similar substance) entering the plant via the roots or shoots and passing through the tissues.2. Physiol. denoting the part of the circulatory system concerned with the transportation of oxygen to and carbon dioxide from the body in general, esp. as distinct from the pulmonary part concerned with the transportation of oxygen from and carbon dioxide to the lungs.DERIVATIVES: sys·tem·i·cal·ly / -ik(ə)lē/ adv.
Refers to a general condition of process or system, rather than a condition of one of the component pieces. For example, when a plant wilts in response to drought , the entire organism is responding to the effect of loss. Communities of plants and animals and their abiotic environment comprise an ecosystem . Whole ecosystems may respond to an event, such as changes in local climate , by undergoing a systemic change—for example, the composition and abundance of species may be altered, and the functional ecological processes of those organisms would be rearranged.