synergismn.

1880 Med. Rec. (N.Y.) 24 Apr. 445/2 The symmetry of the face you know is maintained with all its wondrous mimetic powers by the synergism of numerous pairs of muscles placed on opposite sides.

1892 Proc. Royal Soc. 51 68 They revived the view that the efferent distribution of each spinal nerve is based on its physiological function, and that the movement resulting from the excitation of a root is that of a highly coordinated functional synergism.

1912 Colorado Med. 9 72/1 The thyroid and pituitary offer a good example of synergism.

1970 Nature 4 July 71/1 We wish to describe synergism between two distinct populations of cells in the production of cellular immunity.

2012 Med. Engin. & Physics 34 711/2 Muscle recruitment was selected in order to minimise muscle activation..while maximising synergism among the muscles.

1904 Rev. Amer. Chem. Res. 10 168 When both drugs are used, there may be antagonism or synergism, according to conditions.

1938 Ann. Reg. 1937 349 Much research was done on synergism and antagonism of vitamins.

1961 Lancet 12 Aug. 375/2 Combined chemotherapy of acute leukæmia with 6-mercaptopurine plus corticosteroids gave a higher remission-rate than that observed for either of these administered alone... Synergism was not observed with other drug-combinations given for malignant blood diseases.

1977 New Scientist 30 June 767/2 We've done some experiments on cells in culture and you don't get any synergism, you get addition.

1979 Buffalo (N.Y.) Evening News 18 May ii. 23/2 By combining 2,4-D and silvex, the weed killer became more effective... This is known as synergism.

1997 B. Rowlands Which? Guide Complementary Med. 149 Another possible phenomenon is ‘synergism’, whereby the combined effect of two active ingredients coming together is greater than merely double effect of the individual ingredients.