geometrical optics

noun plural but singular in construction

: a branch of optics that deals with those phenomena of reflection and refraction that can be mathematically deduced from simple empirical laws

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