supplement
I
verb
add, add to, amend, amplify, augment, bolster, broaden, buttress, complement, contribute to, enhance, enlarge, enrich, expand, fortify, improve, increase, lengthen, magnify, reinforce, strengthen, subsidize, superadd, widen
II
index
accrue (increase), addendum, addition, additive, adjunct, affix, aid, allonge, amendment (correction), amendment (legislation), annex (add), append, appurtenance, attach (join), attachment (thing affixed), augmentation, boom (increase), codicil, complement, compound, corollary, correlate, enlarge, expand, extend (enlarge), increase, increment, insertion, offshoot, reinforce, reinforcement, replenish, rider
Burton's Legal Thesaurus.
William C. Burton.
2006