key date

noun

plural key dates

: a coin that is the rarest or otherwise most difficult of its series to obtain

The 1909-S wheat penny is considered a key date by collectors.

Word History

First Known Use

1976, in the meaning defined above

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