conservation of momentum

: a principle in physics: the total linear momentum of a system of particles not acted upon by external forces is constant in magnitude and direction irrespective of any reactions among the parts of the system

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

1. Expanded definitions
2. Detailed etymologies
3. Advanced search tools
4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now