sphe·​nop·​sid sfi-ˈnäp-səd How to pronounce sphenopsid (audio)
: any of a class or division (Sphenopsida or Sphenophyta) of primitive vascular plants characterized by jointed ribbed stems, small leaves usually in whorls at distinct stem nodes, and sporangia in sporangiophores and made up of the horsetails and extinct related forms

Word History


ultimately from Greek sphēn wedge + New Latin -opsis

First Known Use

1957, in the meaning defined above

Time Traveler
The first known use of sphenopsid was in 1957

Dictionary Entries Near sphenopsid

Cite this Entry

“Sphenopsid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/sphenopsid. Accessed 15 Jun. 2024.

More from Merriam-Webster on sphenopsid

Love words? Need even more definitions?

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