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}, {add together}, {tally}, {add up}] 2: make an addition by combining numbers; "Add 27 and 49, please!" [syn: {add}, {add together}] [ant: {deduct}, {subtract}, {take off}]