periodoscope

noun

pe·​ri·​od·​o·​scope

ˌpirēˈädəˌskōp

: a table or dial for calculating the probable date of parturition

Word History

Etymology

period entry 1 + -o- + -scope

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