chair form

noun

: one of the stereochemical conformations of a strainless 6-membered ring (as a cyclohexane ring) in which two atoms directly opposite each other in the ring are outside the plane containing the other four atoms, one of the two atoms being above the plane and the other below the plane compare boat form

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!