ac·​ti·​no·​trich·​i·​um | \ ¦ak-tə-(ˌ)nō-ˈtri-kē-əm \
variants: or less commonly actinotrich \ ak-​ˈti-​nə-​ˌtrik \
plural actinotrichia\ ¦ak-​tə-​(ˌ)nō-​ˈtri-​kē-​ə \ also actinotrichs\ ak-​ˈti-​nə-​ˌtriks \

Definition of actinotrichium

: any of the hairy threadlike fibers in the fin fold of an embryo fish which fuse and form the base of the rays

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First Known Use of actinotrichium

1885, in the meaning defined above

History and Etymology for actinotrichium

New Latin actinotrichium, from actin- + Greek trich-, thrix hair + New Latin -ium

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The first known use of actinotrichium was in 1885

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Cite this Entry

“Actinotrichium.” Dictionary, Merriam-Webster, Accessed 9 May. 2021.

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