Complement

Part of speech: noun, verb

Pronunciation: /ˈkɒmpləmənt/

Definitions

1. Something that completes or enhances another thing by adding what is lacking or needed
2. Something that completes or enhances another entity by providing necessary attributes or features
3. An element that, when added to something, improves its overall quality or balance by fulfilling a deficiency

Etymology: The word "complement" and its near-twin "compliment" split from a single Latin ancestor, and the split is the surprising part. Both descend from "complēmentum", meaning "that which fills up or completes", built from "compleō", "to fill up". Over the centuries one form drifted toward the sense of filling a gap and the other toward praise, though they were once interchangeable in meaning. The Latin "compleō" combines "con-", an intensifying prefix, with "pleō", "to fill". The same root gives English "complete" and "plenty", so a complement is literally whatever brings a thing up to full measure. Middle English took the noun from Latin in the medieval period, and its sense of a supplementary part that makes up a whole remained close to that original idea of filling. The verb "to complement" came later and was formed from the noun, so it began as a way of describing the act of supplying what is missing. Today the verb and noun share the same core idea: one thing that improves another by supplying what it lacks.

Synonyms: supplement, addition, enhancement, accessory, counterpart

Antonyms: detractor, removal, deficiency, subtraction, decrease