ros·​tel·​lum rä-ˈste-ləm How to pronounce rostellum (audio)
plural rostella rä-ˈste-lə How to pronounce rostellum (audio)
: a small process resembling a beak : a diminutive rostrum: such as
: an extension of the stigma of an orchid flower
: an anterior prolongation of the head of a tapeworm bearing hooks
rostellar adjective

Examples of rostellum in a Sentence

Recent Examples on the Web One of the traits researchers are keenest to explore is one that would eliminate a flap inside the vanilla flowers called the rostellum. Alex Fox, Smithsonian Magazine, 23 Dec. 2020

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'rostellum.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


New Latin, from Latin, diminutive of rostrum beak

First Known Use

1686, in the meaning defined above

Time Traveler
The first known use of rostellum was in 1686

Dictionary Entries Near rostellum

Cite this Entry

“Rostellum.” Dictionary, Merriam-Webster, Accessed 21 Feb. 2024.

Medical Definition


ros·​tel·​lum rä-ˈstel-əm How to pronounce rostellum (audio)
: an anterior prolongation of the head of a tapeworm often bearing hooks

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