Source : WordNet®

add together
     v 1: determine the sum of; "Add all the people in this town to
          those of the neighboring town" [syn: {total}, {tot}, {tot
          up}, {sum}, {sum up}, {summate}, {tote up}, {add}, {tally},
           {add up}]
     2: make an addition by combining numbers; "Add 27 and 49,
        please!" [syn: {add}] [ant: {subtract}]