actinotrichium

noun

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

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

Word History

Etymology

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

First Known Use

1885, in the meaning defined above

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