Supplemental

Part of speech: adjective

Pronunciation: /ˌsʌplɪˈmɛntəl/

Definitions

1. Functioning as an ancillary component that contributes to the overall enhancement or completion of a primary subject
2. Existing as an additional resource or element intended to bolster or enrich the principal aspects of a matter
3. Serving as an extra part to improve or complete something primary

Etymology: "Supplemental" is a plain formation: the noun "supplement" with the adjective-forming suffix "-al" attached. The noun "supplement" itself comes from Latin "supplementum," from "supplere," meaning "to fill up" or "make complete," built from "sub-" (up from below) and "plere" (to fill). The core idea is therefore one of filling a gap or making something whole. The suffix has a longer trail than the word it is attached to. It descends from Latin "-ālis," which passed through Old French as "-el" and "-al" before arriving in Middle English as "-al," a route shared by countless English adjectives such as "national" and "central." Its Proto-Indo-European ancestry is a distant root that tells us little about how "supplemental" was actually used. In practice, the word means "added for support," describing something brought in to reinforce or complete what already exists, such as a supplemental income or a supplemental oxygen supply. Its sense stays close to the Latin idea of filling a shortfall.

Synonyms: additional, extra

Antonyms: primary, main