The Collaborative International Dictionary
Coccobacterium
Coccobacterium \Coc`co*bac*te"ri*um\, n.; pl. Coccobacteria. [NL., fr. Gr. ? a grain + NL. bacterium. So called from its round shape.] (Biol.) One of the round variety of bacteria, a vegetable organism, generally less than a thousandth of a millimeter in diameter.
Wiktionary
coccobacterium
n. (context biology English) One of the round variety of bacterium.