Synonyms for Additionally:

adv.

additionally (adverb)
incrementally, increasingly.
all (adverb)
to boot.
also (adverb)
besides, not to mention, in addition, And, as well as, furthermore, moreover, Including, together with, likewise, too, further, along with, also.
furthermore (adverb)
And, also.

adv

additionally (adverb)
incrementally, increasingly.
along (adverb)
as well.
also (adverb)
likewise, moreover, And, together with, along with, besides, also, in addition, Including, further, furthermore, as well as, to boot, not to mention, too.
to a greater extent (adverb)
more.

n.

extra, together with something, additional, supplementary. additionally (noun)
to boot, in addition.
in addition (noun)
increase, as well, yet, still, item, more.

Other synonyms:

in addition
yet, more, item.
Other relevant words:
extra, increase, more, yet, as well, item, supplementary, to boot, still, additional.