THESAURUS
besides
above and beyond, added, additionally, along, along with, also, apart from, as well, as well as, aside from, bar, barring, beside, beyond, but, else, except for, excepting, excluding, exclusive of, farther, further, furthermore, in addition, in addition to, into the bargain, likewise, more, moreover, new, not counting, other, other than, otherwise, outside of, over and above, save, then, to boot, together with, too, yet
ROGET THESAURUS
besides
Addition
N
addition, annexation, adjection, junction, superposition, superaddition, superjunction, superfetation, accession, reinforcement, increase, increment, supplement, accompaniment, interposition, insertion, added, additional, supplemental, supplementary, suppletory, subjunctive, adjectitious, adscititious, ascititious, additive, extra, accessory, au reste, in addition, more, plus, extra, and, also, likewise, too, furthermore, further, item, and also, and eke, else,
besides, to boot, et cetera, and so on, and so forth, into the bargain, cum multis aliis, over and above, moreover, with, withal, including, inclusive, as well as, not to mention, let alone, together with, along with, coupled with, in conjunction with, conjointly, jointly, adde parvum parvo magnus acervus erit.