crossed nicols

plural noun

often capitalized N

: two nicol prisms placed one in front of the other and so oriented that their transmission planes for plane-polarized light are at right angles with the result that light transmitted by one is stopped by the other unless modified by some intervening body

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!