What is another word for "additive"?

Roget's Thesaurus (1911) lists these synonyms for "additive": above, accessory, addition, additional, adjectitious, adscititious, alone, along, also, and, ascititious, bargain, besides, boot, conjointly, conjunction, eke, else, extra, forth, further, furthermore, inclusive, into, item, jointly, let, likewise, mention, more, moreover, not, over, plus, subjunctive, supplemental, supplementary, suppletory, the, together.