interactionn.

1832 I. Taylor Saturday Evening (1833) 86 The reaction, or rather interaction, which at present is going on between readers and writers.

1852 Fraser's Mag. 45 264 The results of the interaction of so many different agencies.

1883 G. Allen in Gentleman's Mag. Oct. 313 The close interaction between the vegetable and animal worlds.

1930 Proc. Royal Soc. A. 129 4 The simplified interaction which couples the nuclear system and the electron.

1951 T. Parsons et al. in T. Parsons & E. A. Shils Toward Gen. Theory Action ii. iv. 190 The specific interaction systems of ego.

1955 H. B. G. Casimir in W. Pauli Niels Bohr & Devel. Physics 130 The electrostatic interaction energy is e²/a where a is a distance between electrons.

1959 Listener 9 July 52/1 There are four distinct types of force through which the manifold transformations of matter and energy arise. These forces are known as the strong, the electromagnetic, the weak and the gravitational interactions.

1964 Language 40 242 An interaction cycle between the mother and child that amounts to a pair of reciprocal transformations.

1967 J. M. Argyle Psychol. Interpersonal Behaviour vii. 128 If A presents himself as an upper-class person but B reacts to him as a working-class person, interaction will not proceed smoothly.

1886 J. F. Smith in Encycl. Brit. XXI. 412/1 The sum of being consists of the two systems of substantial forms and interactional relations.