be·ta·coc·cus I. \ˈbēd.əˌkäkəs\ Etymology: New Latin, from Latin beta beet + New Latin coccus synonym of leuconostoc II. noun (pluralbetacoc·ci \-äˌkī, -äkē, -äkˌsī, -äksē\) Etymology: New Latin, from Latin beta beet + New Latin coccus : a heterofermentative streptococcus