perissad

noun

pe·​ris·​sad

pəˈrisəd,

-iˌsad

plural -s

1

obsolete : an element or radical of odd valence

2

: an element of odd atomic number

—contrasted with artiad

Word History

Etymology

Greek perissos beyond the regular number or size, superfluous, excessive, uneven (from peri around, beyond) + English -ad

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!