Actinosphaerium
noun
Ac·ti·no·sphae·ri·um
¦ak-tə-(ˌ)nō-ˈsfir-ē-əm
: a genus of large freshwater protozoans (order Heliozoa)
Word History
Etymology
New Latin, from actin- + Greek sphairion little ball, diminutive of sphaira ball, sphere
First Known Use
1879, in the meaning defined above