second law of motion se·cond·la·wofmotion uncommon noun 1. the rate of change of momentum is proportional to the imposed force and goes in the direction of the force Synonymssecond law of motionNewton's second law of motionNewton's second law Related words Broader terms Newton's law of motion WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.
