eleutherococcus (??lju???r???k?k?s) n, pl eleutherococci (Plants) a shrub, Eleutherococcus senticosus, which is found in Siberia and which is used in herbal medicine. It supposedly increases stamina and boosts the immune systemCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014