This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. Additional; added to supply what is wanted.

Same as supplemental.

Especially, in anatomy and zoology, additional (to what is normal, ordinary, or usual); added, as something secondary, subsidiary, or useless; supernumerary; extra: as, a supplementary digit (a sixth finger or toe).

adj. functioning in a supporting capacity

adj. added to complete or make up a deficiency

"That these verses are entirely supplementary is the simplest and most natural view of them."

secondary    additive   

supplementary eye    supplementary spleen    supplementary proceedings    supplementary bladder    supplementary curve    supplementary respiration   

additional    supplemental    suppletive    suppletory    parergal    accessory   

alimentary    complementary    complimentary    documentary    elementary    entry    gentry    parliamentary    plenary    rudimentary   

supplemental    introductory    forego    additional    miscellaneous    adequate    preliminary    biographical    exhaustive    relevant