supplemental

Supplemental is an adjective describing something added to complete or augment something else. It signals an extra component, resource, or service that supports a primary item, system, or process. The term comes from Latin supplementum, meaning something that fills up or completes. In common use, supplemental is applied across domains to denote additions rather than replacements: supplemental income, supplemental materials, supplemental insurance, or supplemental oxygen.

In education, supplemental materials or tutoring are provided to reinforce core instruction or address gaps. In finance and employment, supplemental pay or benefits augment a regular salary or primary policy. In healthcare, supplemental oxygen supplies additional oxygen; dietary supplements are products intended to augment the diet, while not substitutes for medical treatment. In public policy, several programs use the word in their official titles, such as Supplemental Security Income and Supplemental Nutrition Assistance Program, indicating benefits that supplement base support.

In publishing and data management, supplementary or supplemental information accompanies a work, offering methods, datasets, or figures not included in the main text. The term can also describe accompanying equipment or resources that enhance a primary system, such as supplemental equipment in a facility or supplemental classroom resources. Overall, supplemental conveys additive purpose and is often used to distinguish elements that are optional or supportive from core components, with usage varying by field.