something added to complete a thing, supply a deficiency, or reinforce or extend a whole.

a part added to a book, document, etc., to supply additional or later information, correct errors, or the like.

a part, usually of special character, issued as an additional feature of a newspaper or other periodical.

Geometry . the quantity by which an angle or an arc falls short of 180? or a semicircle.

to complete, add to, or extend by a supplement.

to form a supplement or addition to.

to supply (a deficiency).

noun

base , core

verb

subtract

noun

added feature , addendum , addition , additive , appendix , bell * , bells and whistles * , codicil , complement , continuation , extra , insert , option , postscript , pullout , rider , sequel , spin-off * , subsidiarynotes:augment means to add more of the same thing; supplement means to add something , [[usually to make up for a deficiencycomplement means an addition will serve to complete something or form with it to make a whole while a supplement is an addition to something already regarded as complete or whole; complement can also mean \'the full quantity]] , number , or amount\' , accessory , adjunct , appendage , appurtenance , addenda , additament , annex , paralipomena , pendant

verb

add fuel to fire , augment , beef up * , build up , buttress , complement , complete , enhance , enrich , extend , fill out , fill up , fortify , heat up , improve , increase , jazz up , pad * , punch up , reinforce , step up , strengthen , subsidize , supply , topnotes:augment means to add more of the same thing; supplement means to add something , [[usually to make up for a deficiencycomplement means an addition will serve to complete something or form with it to make a whole while a supplement is an addition to something already regarded as complete or whole; complement can also mean \'the full quantity]] , number , or amount\' , fill in , round , accessory , add , addendum , addition , additive , annex , appendix , attachment , eke , rider