supplementary

adjective

sup·​ple·​men·​ta·​ry ˌsə-plə-ˈmen-tə-rē 

-ˈmen-trē

1

: added or serving as a supplement : additional

supplementary reading

2

: being or relating to a supplement (see supplement entry 1 sense 3) or a supplementary angle

Synonyms of supplementary

• auxiliary
• additional
• supplemental
• accessory

Examples of supplementary in a Sentence

a list of supplementary material for the class

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

Recent Examples on the Web

Natural Fertilizer Aside from conserving soil moisture, natural or pelleted wool also helps feed the soil and can be used as a supplementary fertilizer in organic gardens. — Lauren Landers, The Spruce, 20 July 2026

The supplementary motor area helps organise their sequence, and the primary motor cortex sends commands to the muscles of the trunk, shoulder, arm and wrist. — Michelle Spear, Scientific American, 11 July 2026

With two satellites at supplementary inclinations, the Newtonian perturbations are equal and opposite in the two orbital planes and cancel each other out. — Jacek Krywko, ArsTechnica, 10 July 2026

The LLCs contested, arguing the alter ego finding was inapplicable and Illinois law didn't permit such piercing in supplementary proceedings. — Jay Adkisson, Forbes.com, 7 July 2026

Word History

Etymology

supplement entry 1 + -ary entry 2

First Known Use

1667, in the meaning defined at sense 1

Phrases Containing supplementary

• supplementary angle

Rhymes for supplementary

• alimentary
• complimentary
• documentary
• parliamentary
• rudimentary
• sedimentary
• testamentary
• integumentary
• uncomplimentary
• unparliamentary
• interparliamentary
• metasedimentary

Kids Definition

supplementary

adjective

sup·​ple·​men·​ta·​ry ˌsəp-lə-ˈment-ə-rē 

-ˈmen-trē

1

: added as a supplement : additional

2

: being or relating to a supplement or a supplementary angle

Medical Definition

supplementary

adjective

sup·​ple·​men·​ta·​ry ˌsəp-lə-ˈment-ə-rē, -ˈmen-trē 

: added or serving as a supplement

supplementary vitamins

Legal Definition

supplementary

adjective

sup·​ple·​men·​ta·​ry ˌsə-plə-ˈmen-tə-rē, -trē 

: added or serving as a supplement