Source : Webster's Revised Unabridged Dictionary (1913)

Additional \Ad*di"tion*al\, a.
   Added; supplemental; in the way of an addition.

Additional \Ad*di"tion*al\, n.
   Something added. [R.] --Bacon.

Source : WordNet®

additional
     adj 1: existing or coming by way of addition; "an additional
            problem"; "further information"; "there will be
            further delays"; "took more time" [syn: {further(a)},
            {more(a)}]
     2: added to complete or make up a deficiency; "produced
        supplementary volumes"; "additional reading" [syn: {supplementary},
         {supplemental}]
     3: further or added; "called for additional troops"; "need
        extra help"; "an extra pair of shoes"; "I have no other
        shoes"; "there are other possibilities" [syn: {extra}, {other(a)}]
     4: more; "would you like anything else?"; "I have nothing else
        to say" [syn: {else(ip)}]
     5: one more or an added; "another chance"; "another cup of
        coffee"; "an additional piece of pie" [syn: {another(a)}]