an·​ti·​prism ¦an-ˌtī-¦pri-zəm How to pronounce antiprism (audio)
plural antiprisms
: a polyhedron having two faces that are identical polygons in parallel planes but rotated from each other while the other faces are a series of alternately oriented triangles
These are the first clusters composed of centered square antiprisms of metal atoms.Francis J. DiSalvo, Science, 9 Feb. 1990
antiprismatic adjective
The ytterbium environment, in keeping with the diminished ionic radius, is now eight-coordinate with a square-antiprismatic arrangement. Glen B. Deacon et al., Canadian Journal Of Chemistry, 1 Jan. 2009

Word History


anti- entry 1 + prism

First Known Use

1969, in the meaning defined above

Time Traveler
The first known use of antiprism was in 1969

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!

Dictionary Entries Near antiprism

Cite this Entry

“Antiprism.” Dictionary, Merriam-Webster, Accessed 29 Feb. 2024.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!