Synonyms of supplementary

supplementary

adjective

ˌsə-plə-ˈmen-tə-rē 

1

as in auxiliary

available to supply something extra when needed

the teacher's edition of the textbook comes with a lot of supplementary material

Synonyms & Similar Words

• auxiliary
• additional
• supplemental
• accessory
• peripheral
• makeshift
• accessorial
• appurtenant
• complementary
• added
• further
• backup
• contributory
• assisting
• substitute
• supportive
• assistant
• another
• subordinate
• excess
• subsidiary
• secondary
• tributary
• surplus
• superfluous
• nonessential
• helping
• adjuvant
• unessential
• dispensable
• subservient

Antonyms & Near Antonyms

• main
• principal
• chief
• basic
• primary
• fundamental
• necessary
• prime
• essential
• integral
• vital
• required
• imperative
• requisite
• needful
• needed
• all-important
• indispensable

2

as in complementary

related to each other in such a way that one completes the other

regards theology and philosophy as supplementary fields of study

Synonyms & Similar Words

• complementary
• reciprocal
• supplemental
• mutual
• collective
• correlative
• combined
• communal
• joint
• cooperative
• symbiotic
• common
• shared
• conjoint
• united

Antonyms & Near Antonyms

• nonreciprocal
• noncomplementary

Example Sentences

Recent Examples of supplementary

Several supplementary online exhibitions let visitors browse some of the collection digitally. — Condé Nast, Condé Nast Traveler, 7 Sep. 2026

Pills and gel capsules Many people incorporate elderberries into their diets as supplementary pills or lozenges. — Bestreviews, Chicago Tribune, 4 Sep. 2026

The sleeping surface measures 82 inches (208 cm) long and is widened via slim supplementary cushions to 57 inches (145 cm) at the head by the doors, tapering to 50 inches (127 cm) at the foot between the wheel wells. — New Atlas, 18 Aug. 2026

In 2024, Purja became the fastest person to summit all 14 of the peaks without supplementary oxygen. — Lex Harvey, CNN Money, 31 July 2026