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