Relating to or involving three or more bodies or particles; specifically with reference to the problem of predicting their positions and motions at any future time given their present values and the way the bodies interact (through collision, gravitational attraction, etc.).
Origin
1920s.
Definition of many-body in US English:
many-body
adjective
Relating to or involving three or more bodies or particles; specifically with reference to the problem of predicting their positions and motions at any future time given their present values and the way the bodies interact (through collision, gravitational attraction, etc.).