Synonyms of the word

supplementary

• adj. Additional; added to supply what is wanted.
• n. Something additional; an extra.

additive

• adj. (mathematics) Pertaining to addition; that can be, or has been, added.
• adj. (mathematics, of a function, etc.) Distributive over addition.
• adj. (algebra) Having addition as an operator.
• adj. (chemistry) Pertaining to chemical addition.
• adj. (genetics) Describing genes (or the interaction etc. of such genes) which govern the same trait and whose…
• n. A substance added to another substance or product for its ability to alter its properties.
• n. (grammar) A word or phrase that adds something, such as also, even, or nor.

auxiliary

• adj. Helping; giving assistance or support.
• adj. Supplementary or subsidiary.
• adj. Held in reserve for exceptional circumstances.
• adj. (nautical) Of a ship, having both sails and an engine.
• adj. (grammar) Relating to an auxiliary verb.
• n. A person or group that acts in an auxiliary manner.
• n. A sailing vessel equipped with an engine.
• n. (grammar) An auxiliary verb.
• n. A marching band colorguard.

secondary

• adj. Next in order to the first or primary; of second place in origin, rank, etc.
• adj. Originating from a deputy or delegated person or body.
• adj. (organic chemistry) Derived from a parent compound by replacement of two atoms of hydrogen by organic…
• adj. (geology) produced by alteration or deposition subsequent to the formation of the original rocks mass.
• adj. (geology) developed by pressure or other causes.
• adj. (anatomy) Pertaining to the second joint of the wing of a bird.
• adj. (medicine) Dependent or consequent upon another disease, or occurring in the second stage of a disease.
• adj. Of less than primary importance.
• adj. (education) related to secondary education, i.e. schooling between the ages of 11 and 18.
• adj. (manufacturing) relating to the manufacture of goods from raw materials.
• adj. (of a color) Formed by mixing primary colors.
• n. (ornithology) Any flight feather attached to the ulna (forearm) of a bird.
• n. (finance) An act of issuing more stock by an already publicly traded corporation.
• n. (American football, Canadian football) The defensive backs.
• n. (electronics) An inductive coil or loop that is magnetically powered by a primary in a transformer or…
• n. One who occupies a subordinate or auxiliary place; a delegate deputy.
• n. (astronomy) A secondary circle.
• n. (astronomy) A satellite.
• n. Used as an abbreviation to refer to items with names containing secondary.

subsidiary

• adj. Auxiliary or supplemental.
• adj. Secondary or subordinate.
• adj. Of, or relating to a subsidy.
• n. A company owned by a parent company or a holding company, also called daughter company or sister company.
• n. (music) A subordinate theme.

supplemental

• adj. Acting to supplement.
• adj. Appending.
• adj. Lacking a regular schedule (as in a supplemental airline).
• n. Something that supplements or adds to.
• n. A requisition or article of legislation that provides additional funding for a program.