Antonyms of adj supplemental

2 senses of supplemental

Sense 1
auxiliary, subsidiary, supplemental, supplementary -- (functioning in a supporting capacity; "the main library and its auxiliary branches")

INDIRECT (VIA secondary) -> primary -- (of first rank or importance or value; direct and immediate rather than secondary; "primary goals"; "a primary effect"; "primary sources"; "a primary interest")

Sense 2
supplementary, supplemental -- (added to complete or make up a deficiency; "produced supplementary volumes")

INDIRECT (VIA additive) -> subtractive -- (constituting or involving subtraction; "a subtractive correction")

Similarity of adj supplemental

2 senses of supplemental

Sense 1
auxiliary, subsidiary, supplemental, supplementary -- (functioning in a supporting capacity; "the main library and its auxiliary branches")
       => secondary (vs. primary) -- (being of second rank or importance or value; not direct or immediate; "the stone will be hauled to a secondary crusher"; "a secondary source"; "a secondary issue"; "secondary streams")

Sense 2
supplementary, supplemental -- (added to complete or make up a deficiency; "produced supplementary volumes")
       => additive (vs. subtractive) -- (characterized or produced by addition; "an additive process")