fivesome n 1: the cardinal number that is the sum of four and one [syn: {five}, {5}, {V}, {cinque}, {quint}, {quintet}, {fivesome}, {quintuplet}, {pentad}, {fin}, {Phoebe}, {Little Phoebe}] 2: five people considered as a unit [syn: {quintet}, {quintette}, {fivesome}]