actinost

A1C3T1I1N1O1S1T1

noun

A bone at the base of a paired fin (of a fish)

OriginAncient Greek ἀκτίς →
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Meanings

nounactinost (plural actinosts)

plural actinosts

  1. biologyA bone at the base of a paired fin (of a fish)

    The second well-developed actinost is below the vertebra supporting the subcaudal blood-vessels, but that is not so strong proximally as the first; the ribs are not directed downwards, but backwards, and are entirely separated from each other.

    1889, Dr. G. Baur, “On the morphology of ribs and the fate of the actinosts of the median fin in fishes”, in Journal of morphology, volume 3

Origin

  1. Ancient Greekἀκτίς“ray”
  2. Englishactinost

From New Latin, from Ancient Greek ἀκτίς (aktís, “ray”) + ὀστέον (ostéon, “bone”).

More words from Ancient Greek

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Rhymes & wordplay

Anagrams

Scottianoscitant
Cite this entry
APA

actinost. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/actinost

MLA

“actinost.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/actinost. Accessed November 3, 2026.

Chicago

WatkinsX Dictionary, s.v. “actinost,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/actinost.

Source: actinost on Wiktionary, CC BY-SA 4.0.